Title: Dr. Lucas Macri on the Extragalactic Distance Scale

Organization: Slacker Astronomy – http://www.slackerastronomy.org/

Podcaster: Michael Koppelman

Description: Michael Koppelman from Slacker Astronomy interviews Lucas Macri, an astronomer from Texas A&M, about his work on the cosmic distance ladder using extragalactic cepheid variable stars.

Bio: Slacker Astronomy is a light-hearted podcast that wanders the astronomical road-less-traveled. Visit us at http://www.slackerastronomy.org/.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by This episode of “365 Days of Astronomy” is sponsored by Elizabeth Fracek, and dedicated to the Chicago Academy of Sciences, the original home of my good friend, the Atwood Sphere.

Transcript:

Michael Koppelman: Hello again. Welcome to the 365 Days of Astronomy podcast hosted by Slacker Astronomy. This is Michael from Slacker Astronomy and slackerastronomy.org the amusing byways of astronomy and science podcasting by astronomers, amateurs and you.

We have an interview today with a great professional astronomer from Texas A & M University. Lucas Macri is going to talk to us about the cosmic distance scale, the distance ladder and his work on it, getting it to finer and finer precision. The whole interview is over at slackerastronomy.org. It’s really good. The part I had to cut out is good.

You should go listen to it at slackerastronomy.org. In the meantime we have something like 9 minutes and 17 seconds of the interview following and I hope you enjoy it. Here we go with me interviewing Lucas Macri about the cosmic distance scale.

Michael: Hey everybody I’, here with Lucas Macri who is a Doctor of Astronomy and you are out of Texas right now, right Lucas?

Dr. Lucas Macri: Hi Michael. Yeah I’m an assistant professor of astronomy at Texas A&M University.

Michael: Well, see you’re a Texan. How do you like that?

Lucas: It’s nice. I’ve been here for about two years in College Station. I’m part of a new astronomy group in the Physics and Astronomy department. We’re just getting started which has its challenges but also a lot of opportunities so it is cool.

Michael: You’re originally from Argentina, yes?

Lucas: Yes, that’s right.

Michael: In fact, we met in Argentina which was a blast. I had a lot of fun at that conference.

Lucas: Yeah the American Association of Variable Star Observers meeting. It was really nice. I had never been to one of those even though I lived in Boston for 11 years. I guess I was within a mile of AAVSO headquarters. Shame on me but it was really cool to meet all the people involved in Mendoza and enjoy the southern sky. It was nice.

Michael: I hear you’re an AAVSO member now?

Lucas: Yes, I remedied that travesty.

Michael: I’m sorry about your World Cup team. Were you following that?

Lucas: Yeah but you know Germany lost today so I’m feeling pretty good.

Michael: You gave a talk at the AAVSO meeting in Mendoza, Argentina about the Cosmic Distance Ladder and essentially some of the research you’ve been doing in that topic. Can you tell us a little bit about what you’re studying there?

Lucas: Sure. The Cosmic Distance Scale or the Extra-galactic Distance Scale is a generic term for the different techniques that astronomers use to measure distances between galaxies. About a hundred years ago a lady by the name of Henrietta Leavitt was working as a researcher at Harvard College Observatory. She discovered this class of variables known as cepheid variables, exhibited a very striking correlation between the period of their pulsation and their brightness.

Back then they didn’t know what the physical reason was for this but they realized that they had something good when they saw it. Miss Leavitt essentially what she discovered was what we now call the cepheid period luminosity relation.

This is a really good way of measuring distances between galaxies as long as those galaxies have this type of variable known as a cepheid. It works very well for any galaxy that has had a recent star formation. It works for spiral galaxies or the regular galaxies.

The cepheid phase is the end of the lifetime of a very massive star somewhere between four and twelve solar masses. Cepheids then are one of the many ways that astronomers have nowadays of measuring distances to galaxies. It is one of the most reliable I would argue since I work with them. I have to say that, right? [Laughter]

They’re pretty good and with the launch of the Hubble Space Telescope twenty years ago, especially after the servicing mission in 1994 when Hubble’s vision was restored to its design specifications. Astronomers have been able to discover cepheid variables further and further away from the Milky Way.

In the days of the wide-field planetary camera II which was in Hubble from 1994 until last year we could, not easily, but we could detect cepheid variables all the way out to almost 20 mega parsecs. That’s 60 million light years, give or take a few. That’s far enough that you can actually calibrate what we call secondary distance indicators.

Once you have a secondary distance to a whole bunch of galaxies then you can try to understand or you can try to calibrate something else that is brighter and you can actually take much further out. One of the best secondary distance indicators we have are what we call a temporary supernovae which are the explosions that occur when a white dwarf goes over 1.4 solar masses, probably due to the accretion of material from a neighboring star although we don’t know exactly why temporary supernovae blow up.

We do know that they explode and when they do, they outshine every other star in the galaxy where they are. They can be seen basically to the edge of the universe if you have a large enough telescope or if you expose your telescope long enough. With temporary supernovae you can actually reach much larger distances. You can go all the way out into what we call the Hubble flow.

Those are distances far enough away from the Milky Way that the galaxies that you are looking at are essentially receding from us due to the expansion of the universe and due to the Big Bang. So by doing this then we can use cepheid variables and temporary supernovae and measure distances to very distant galaxies.

By looking at the correlation between the distances to those galaxies and the recession velocities that they exhibit that’s the famous plot that was first made in the 1920s by Edwin Hubble by showing that more distant galaxies appear to recede faster from us. He realized that was evidence for the Big Bang. But also the slope of that correlation tells you essentially the age of the universe times a correction factor that has to do with the amount of stuff in the universe whether it is matter, or dark energy.

That sort of changes the number that you want to multiply that slope by. But in general it tells you the sort of the age of the universe. The better that we can measure distances to galaxies by using cepheids the better then we can calibrate the luminosity of temporary supernovae, the better we can measure or estimate the Hubble constant and therefore estimate the age of the universe.

A couple years ago Adam Reese, myself, and a whole bunch of other collaborators finished a project where we used the Advanced Camera for Surveys on Hubble and the NICMOS camera to do optical observations of near infrared observations of cepheid variables in six galaxies that had previously hosted the temporary supernovae explosion. We used that to calibrate the entire Cosmic Distance Ladder and measure the Hubble Constant with an accuracy and precision of about five percent. This actually means that we measured the universe to about five percent.

Michael: That’s awesome. So, you’re actually doing what many amateur astronomers do in that you’re getting light curves of these stars except just using space-borne really cool cameras.

Lucas: Yeah, I’m pretty lucky in that sense. Today I was working with some really cool new images from the Wide Field Camera 3, which is the latest optical in near-infrared camera was installed by the astronauts during the last servicing mission to Hubble. It’s a very sweet instrument.

The finest samples of a resolution that Hubble can deliver by the angular resolution of Hubble, the big saucer only one twenty-fifth of an arc second across, like .04 arc seconds per pixel. It makes all the previous cameras on Hubble, especially with big 2 which was really cool to have back in 1994, but by last year it was showing its age. It has been there 15 years in space – a lot of radiation damage and for Hubble, fairly large pixels, about a tenth of an arc second.

Now you have two and a half times further refinement in the resolution of the camera and it is pretty fast in the sense that for the same amount of exposure time you can go a lot deeper. That allows us to discover cepheids much further away than we were able to do before, not only in the optical but also more importantly in the near-infrared where the improvements they were likened to NICMOS which was the previously infrared camera is quite dramatic. Now we can do in two hours what before would have taken us 30 hours. It’s also a great way of saving Hubble time for other important projects.

Michael: That’s awesome. Is there some record like the farthest away galaxy we’ve ever measured a cepheid in?

Lucas: Well for cepheids another team of astronomers led by Kem Cook at Lawrence Livermore National Lab – I was a member of that team – attempted to measure cepheid variables in the ——– 11:17 cluster. That is a hundred mega parsecs away. That’s really difficult even for Hubble.

We had to do a couple of hours worth of integration just at one time to try to reach a percentage which would essentially be about around a 30th magnitude. We got the time and were all set and were starting the project, unfortunately this was at a time when the Advanced Camera for Surveys which is another great camera installed on Hubble in the late nineties, by the time we were doing our observations, 45 days into our sequence the camera had a short circuit. It didn’t recover for a long time…

Michael: Oh yeah, you broke ACS.

Lucas: Well fortunately it wasn’t [laughter] exposing on our object when it short-circuited. That would have probably resulted in our termination from future Hubble observations. No, it wasn’t anyone’s fault it was just radiation damage or just bad luck.

Whatever happened, the ACS died and eventually astronauts replaced one of the circuit boards and now it is back up and running on at least two of the channels I believe. We were actually able to get some pretty tantalizing evidence that there are things that are varying like you would expect cepheids to vary, but our observation only spanned 45 days.

Typically if you want to claim that you discovered a cepheid you want to see at least one whole period of pulsation. So for the things that we were targeting in COMA 13:05 we were hoping to discover things in 50 days and one hundred days. We didn’t quite make it.

Michael: How far away did you say that is?

Lucas: Comaclast13:16 is about 100 mega parsecs away. That is about 325 million light years. The reason we were targeting that was we were hoping then to have a cepheid distance directly to a galaxy that’s receding from us purely due to the expansion of the universe instead of having to jump from cepheids to type one13:39 supernovae. But that didn’t work out.

With the Wide Field Camera 3, Adam, Reese, myself, and a number of other collaborators were now targeting galaxies that are sort of 35 mega parsecs away from us. Whereas the COMA project was really stretching Hubble and using a lot of orbits to achieve our goal, here with WFC3 we can routinely discover hundreds of cepheids actually in galaxies that are much further away than what we could do 18 years ago. So, that’s pretty good.

Michael: That’s awesome.

Lucas: The new camera has essentially doubled or even tripled the volume that we can access with Hubble. That really helps a lot for trying to calibrate the luminosity of type one supernovae to greater accuracy and precision.

Michael: Where are you going next when you envision your career? What do you want to dig into in the long term?

Lucas: In the short to medium term we’re hoping in the next agency cycle to get time to do a few more type 1a supernovae calibrators so that we can actually measure the Hubble Constant to about two percent.

After that we probably need to wait for a European mission called Gaia that is going to go up hopefully in 2012 that is going to measure parallaxes. It is a very venerable Asian technique but the one that works the best for measuring distances to stars within the Milky Way.

We hope that Gaia will actually measure parallaxes to hundreds of cepheids within our own galaxy. That will allow us to calibrate the cepheid period also in relation to an accuracy well below, much better than one percent. Eventually, a decade from now we might actually have a one percent measurement of the Hubble Constant.

This is important not only for knowing the age of the universe to that level of accuracy and precision but also because the better you measure the Hubble Constant the better you can constrain the properties of dark energy.

We know dark energy is this mysterious component of the universe which appears to be dominating its current expansion rate and driving that expansion to an accelerated régime. We want to know what exactly dark energy is and one of the ways that we can try to understand better is by measuring what we call its equational state.

To measure that more precisely you need to know the age of the universe as well as possible. That’s what is driving us in the short to medium term.

Michael: Got it.

Lucas: In the long term Texas A&M University is one of the founding partners of the giant Magellan telescope which will be a 25 meter telescope located in northern Chile. It will be ten times bigger in diameter, larger than Hubble. It’s going to deliver, we hope, diffraction limited images meaning that it will actually give you images ten times sharper than Hubble at least in the near infrared.

Because it is ten times larger in diameter means it has a hundred times the collecting area. You’ll be able to go very deep with excellent image quality. That will be a very nice toy to have. We hope it will be ready by 2017-2018 at a cost of about a billion dollars – give or take a few hundred million. That’s really going to be great.

It is going to be located just a short distance away from the Large Synoptic Survey Telescope which is another really great project coming up in the next decade. It is going to survey the entire sky every two or three days. It will essentially make the first movie of the sky for stellar variability.

As some of your listeners out there who are variable star observers, which is going to have thousands of new supernovae exploding and detected every night. All the variable stars you can dream of across five different bands from the UV to the near infrared and that telescope is going to discover so many things. It has some very clearly stated primary science goals like measuring dark energy better, discovering all the asteroids in the solar system that could be harmful to mankind.

I think what’s going to be really sweet is all the things that LSST is going to discover that we have no idea are out there. This is the first time that we’re going to be staring deep into the universe with a cadence of minutes and hours and days and years.

Who knows what we’ll find? To have a 25 meter class telescope available for follow-up especially spectroscopic follow-up will be crucial. That’s sort of a decade away but it’s a really, really promising future.

Michael: How awesome. That’s amazing. Thank you very much. Dr. Lucas Macri from Texas A&M University and an all around good guy and fellow fan of Dulce Deleche, like that’s a part of my life now.

Lucas: Very good.

Michael: Which I’ve talked about on this podcast. Thanks a lot Lucas, I appreciate it.

Lucas: Thank you Michael back to you soon.

Michael: Remember there’s more over at slackerastronomy.org so check it out.

This transcript is not an exact match to the audio file. It has been edited for clarity. Transcription and editing by Cindy Leonard.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: A Zoo of Active Galaxies

Podcaster: Chris Lintott and Kevin Schawinski

Organization: www.galaxyzoo.org

Description: Chris and Kevin celebrate Galaxy Zoo’s 3rd Anniversary by discussing a new paper published by the Galaxy Zoo team that studies active galactic nuclei.

Bio: Chris Lintott is an English astrophysicist. He is a post-doctoral researcher who is involved in a number of popular science projects aimed at bringing astronomical science to a wider audience. He is the co-presenter of Patrick Moore’s BBC series “The Sky at Night” and a co-author of the book Bang! – The Complete History of the Universe with Patrick Moore and Queen guitarist Brian May. Chris Lintott is one of the principal investigators for the Galaxy Zoo project, and runs Zooniverse projects which allow you to help scientists explore the Universe. Chris is now the Director of Citizen Science Initiatives at the Adler Planetarium in Chicago.

Kevin Schawinski is an Einstein Fellow at the Yale Center for Astronomy & Astrophysics. He is a co-founder of Galaxy Zoo and also contributes to the Galaxy Zoo blog.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by John Sandlin because a little astronomy illuminates the darkest nights.

Transcript:

CL : Hello, I’m Chris Lintott. I’m one of the principal investigators for the Galaxy Zoo project which has involved more than 300,000 people in classifying galaxies which were imaged by the Sloan Digital Sky Survey or Hubble Space Telescope. Each of those people turned up at galaxyzoo.org and told us about the shape of the galaxies.

When we launched the project 3 years ago today I don’t think we had any idea that it would be so successful, or that we’d find out as much about the galaxies as we did. Joining me to discuss the latest results is Kevin Schawinski, now a researcher at Yale University but at the time that Galaxy Zoo launched my colleague in Oxford. Good morning

KS : Good morning.

CL : The latest results are all to do with AGN, active galactic nuclei. So what are AGN, and why are they important?

KS : An AGN is an Active Galactic Nucleus, the nucleus of a galaxy that seems to be emiting prodigious amounts of energy, radiation, light. AGN have been known for some time, but it took quite a few years of research before people understood that the only power source that could drive AGN were accreting supermassive black hole.

CL : We now know, don’t we, that most galaxies in the Universe have a big black hole at their centre. Where does the evidence for that come from?

KS : We’ve used observatories like the Hubble Space Telescope as well as ground based telescopes to look at the very centers of nearby galaxies and there we find evidence for huge amounts of mass concentrated in the very nucleus. We know this from the motion of stars around the centre…

CL : …we just measure how quickly they’re moving

KS : When you work out how much mass is contained in that very center you come up with a number that’s enormous, millions or even billions of times the mass of the Sun and there’s no way that could be anything other than a supermassive black hole. We even see this at the center of our own Milky Way where there’s an empty spot with stars whizzing round it at hundreds of kilometres a second, and we now know that this could be nothing other than a supermassive black hole.

CL : OK, so we have massive black holes at the center of the galaxy, but there’s something confusing here. You talked about these AGN giving out huge amounts of radiation, and light, but the only thing everyone knows about black holes is that they don’t emit light, so how can you get these huge amounts of energy from black hole.

KS : It’s an irony that the brightest objects in the Universe are actually black holes. The light that we see from black holes doesn’t come from inside the black hole because as we all know light can’t escape them – the light actually comes from material, from gas and dust as it is being sucked into the black hole. As it screams into the black hole it forms this dense disk of material as it spirals into the black hole…

CL : what we call the accretion disk…

KS : the material gets compressed, there’s friction and it gets heated up, and suddenly you have an object – this accretion disk – that’s extremely hot and extremely luminous, and if our line of sight is not blocked in any way that’s what we see. And in the case of large black holes feeding essentially as fast as they can this tiny little accretion disk can be brighter than the 100 billion or so stars in the galaxy around it, and all we see is the material falling into the black hole.

CL : So that’s the basic process, but does this happen with all galaxies that have black holes.

KS : If we look around us only a tiny fraction of galaxies, perhaps a few percent, are actively feeding today. However, we also known from large scale studies that most black holes must have grown in an active galactic nucleus, an AGN phase. So we believe that every galaxy went through an active, feeding phase that established the black hole at its center.

CL : So, for example, although the Milky Way is quiet today, in the past it might have been an active galaxy.

KS : That’s the idea.

CL : How does Galaxy Zoo come into this? How have the Galaxy Zoo results helped us understand AGN?

KS : SSo one of the puzzling things about black holes and galaxies is that even though we think of black holes as this destructive force, they’re actually really tiny compared to the galaxies they live in. Their gravitational pull doesn’t go much further than the very center of the galaxy, and so we wouldn’t naturally expect the black hole to be in any way linked to the rest of the galaxy

CL : When you say ‘linked’ do you mean they should have no influence on the rest of the galaxy?

KS : It shouldn’t have much influence, and what people have found is that for some mysterious reason the mass of the black hole is linked very tightly to the mass of the galaxy around it.

CL : So the bigger the black hole, the bigger the galaxy

KS: The bigger the black hole, the bigger the galaxy, so somehow they must have grown together, so somehow the material falling into the black hole controls the growth of the stars in the galaxy around it. Now what we did with Galaxy Zoo was that we wanted to know what kinds of galaxies have currently feeding black holes in the Universe around us, and what this tells us about how this link between black holes and galaxies is established.

CL : When you say kinds of galaxies, what do you mean?

KS : The biggest question that Galaxy Zoo let us address is what kinds of galaxies are actually spiral, and what kinds are elliptical galaxies – football or rugby ball shaped galaxies. So what we wanted to know was whether growing black holes are most likely to occur in spiral or elliptical galaxies.

CL : And that’s what the paper you recently published directly addresses, so what’s the answer? Where are the active galaxies in our local Universe?

KS : Most of the active galaxies – up to 90% – are actually in galaxies with some sort of disk, about half of them in beautiful grand design galaxies like the Milky Way. One of the things we learnt from the Galaxy Zoo results is that the type of galaxy that is most likely to be growing its black hole today is actually a galaxy like our own Milky Way – the kind of mass, and the kind of disk we see in the Milky Way

CL : You sound quite surprised by that…

KS : It is surprising because when we look at our own Milky Way, in the centre, the black hole is virtually invisible. We see stars going around it but we don’t see it feeding. What the x-ray community has known from quite a while is that when you look at the clouds of molecular gas and material around the black hole of the Milky Way, you see an echo of past activity. Maybe a few hundred or a few thousand years ago the black hole has been much more active.

CL : Does that mean that these things can switch on and off? That maybe a galaxy isn’t always active or always quiet, but can switch between the two.

KS : That’s right, and it gives more context to that finding that our Milky Way has been active recently. It now makes much more sense because it’s galaxies like our Milky Way that have been active recently.

CL : What about elliptical galaxies? Do they have AGN?

KS : They do. 10% of all AGN sit in elliptical galaxies, and this is where the big surprise came in. When you look at spiral galaxies it is preferentially the most massive spiral galaxies with the biggest black holes that are feeding their black holes today.

CL : So the bigger the spiral galaxy, the greater the chance that it will be active.

KS : That’s right, but in ellipticals it’s exactly the opposite. It’s more likely for an early-type galaxy will be feeding its black hole today the smaller the elliptical galaxy and the smaller its black hole is.

CL : So it’s the small elliptical galaxies that are active. Does that mean that they’re behaving in a fundamentally different way from the spirals, that something else is going on, or is that just the way things turned out?

KS : That’s what we concluded in the paper. There seem to be two very different ways in which black holes can grow and co-evolve with the galaxy they live in, depending on whether you have a spiral galaxy or an elliptical galaxy.

CL : So what are the different modes?

KS : We believe that galaxies like the Milky Way are pretty stable systems – they have these large rotating disks that are very difficult to disrupt. We know our own Milky Way hasn’t been through any major changes probably within the last 10 billion years or so. So whatever process is feeding the black hole and leading to energy being released by the black hole doesn’t seem to have much of an effect on galaxies like the Milky Way.

CL : OK, so the black hole does its own thing, and we sit out here and we’re perfectly happy and the galaxy remains stable. But in ellipticals something else is happening.

KS: When we look at the galaxies that have growing black holes that are ellipticals, we find that in almost all cases they’re galaxies that have recently shut down their star formation so they used to be forming lots of young stars, but by the time we see a growing black hole they’ve stopped forming stars. So somehow in elliptical galaxies, black hole growth and AGN phases seem to be associated with shutting down star formation to go from an actively star-forming blue galaxy to a passively evolving dead and red galaxy.

CL : But that’s remarkable, because you said earlier that the black hole should have very little effect on the galaxy. How can the presence of an active black hole have such a dramatic effect on star formation throughout the whole galaxy?

KS : The hypothesis is that the energy liberated as material falls into the black hole giving you this bright powerful AGN or quasar phase, that if you just take a little bit, a small fraction of that energy and have that energy heat up the gas and dust that forms stars, then the jets, the wind, the radiation from the black hole could sweep the galaxy clear of its gas and dust and remove the fuel from star formation. The black hole doesn’t just starve itself because it’s blowing out any further material that could trickle down to the centre, but it’s also preventing any more stars forming in that galaxy. Even though its gravitational reach doesn’t go beyond the very centre, the energy liberated by the black hole as it feeds can effect the galaxy as a whole.

CL : You’ve talked mostly about the local Universe, but the process that you’re describing that sometimes goes by the name of AGN feedback, we think that was more important in the early Universe.

KS: So this is where the surprise that it’s the least massive early type galaxies that are still feeding their black holes and stopping their star formation comes in. We know that the most massive galaxies in the Universe – which are also elliptical – they formed in the early Universe, so what we’re seeing here is an anti-hierachical, an inverse growth. It’s the most massive early-type galaxies that formed first and went through both the black hole growth phase that shuts down star formation in the early Universe, while their small cousins are going through this process today.

CL : Excellent, so by studying the local Universe we can find out about our Universe’s early days. Kevin, thanks for joining us.

Galaxy Zoo is currently taking a look deep into the Universe with images from the Hubble Space Telescope, to try and address some of the questions that Kevin was describing. To take part, go to www.galaxyzoo.org.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: A 365 Days Classic: Will the World End in 2012?

Description: Today’s episode is an encore presentation of a previously aired podcast. To ensure that 365 Days of Astronomy can provide new podcasts every day of the year, please consider signing up to contribute your own podcast. Or if you are already on the schedule for a 365 Days of Astronomy podcast, please make sure you submit your materials in timely manner. But for today, we hope you enjoy this 365 Days of Astronomy classic.

Podcaster: Cameron Hummels from Columbia University

See the original posting from April 27, 2009 (which includes the transcript and more info)

Today’s sponsor: “Between the Hayabusa homecoming from Itokawa and the Rosetta flyby of asteroid Lutetia, 13 June until 10 July 2010, this episode of ’365 Days of Astronomy’ is sponsored anonymously and dedicated to the memory of Annie Cameron, designer of the Tryphena Sun Wheel, Great Barrier Island, New Zealand, a project that remains to be started.”

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: How to View a Meteor Shower

Podcaster: Frasier Cain and Dr. Pamela Gay

Organization: Astronomy Cast – www.astronomycast.com

Description: Fraser and Pamela discuss the upcoming Perseid Meteor shower and provide tips for the best viewing.

Bio: Astronomy Cast takes a fact based journey through the cosmos as it offers listeners weekly discussions on astronomical topics ranging from planets to cosmology. Hosted by Fraser Cain (Universe Today) and Dr. Pamela L. Gay (SIUE), this show brings the questions of an avid astronomy lover direct to an astronomer. Together Fraser and Pamela explore what is known and being discovered about the universe around us.

Today’s sponsor: Michael Geoff has sponsored this mysterious episode of Astronomy Cast as one of the many “365 days of astronomy”.

Transcript:

Coming soon… (dun dun dun)

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: A Spaceport of Her Own

Podcaster: Dr. Alex “Sandy” Antunes

Organization: Antunes, Project Calliope LLC – http://projectcalliope.com

Description: Setting up a privace rocket site in the remote Tropics sounds like a movie supervillain plan, but Randa Milliron of InterOrbital Systems (InterOrbital.com) explains why it’s the best way to get us to orbit and beyond.

Bio: Sandy looks at the science and the people in today’s 9-5 pro astronomy world. Born in the heart of a dying star (as we were all), Alex draws from his research, writing, and game design work to bring you the joy of science twice a week at ScientificBlogging.com/skyday– and to launch the first personal science/music satellite via ProjectCalliope.com.

Today’s sponsor: “Between the Hayabusa homecoming from Itokawa and the Rosetta flyby of asteroid Lutetia, 13 June until 10 July 2010, this episode of “365 Days of Astronomy” is sponsored anonymously and dedicated to the memory of Annie Cameron, designer of the Tryphena Sun Wheel, Great Barrier Island, New Zealand, a project that remains to be started.”

Additional sponsorship for this episode of 365 Days of Astronomy is provided by Chuck McCorvey.

Transcript:

[Sandy intro] Welcome to another segment with the Daytime Astronomer. I’m Dr. Sandy Antunes and you can read me twice a week at ScientificBlogging.com under ‘the Satellite Diaries’. I’m going to be presenting a section of an interview with Randa Milliron, the CEO of InterOrbital Systems. They’re the TubeSat people, and I’m launching a satellite with them, the ProjectCalliope.com project, ‘Music from Space’. This segment had several possible titles- ‘From Paradise to Outer Space’, ‘To Titan’, ‘She Owns a Rocket Company’. We’re going to be talking about the hows and whys of having your own private spaceport in this segment on 365DaysofAstronomy. Now, we’re going to go into this somewhat abruptly, I apologize for the phone quality audio for it, but it’s four and a half minutes of crunchy sci tech goodness. Enjoy.

[Sandy] The motto at NASA for a while was better/faster/cheaper with, of course, the quip being “pick any 2″, do you think all 3 are achievable: better/faster/cheaper?

[Randa] I think they are achievable, that’s the mantra in many industries, but in terms of one’s approach, in our case I believe we’ve come up with a magic triangle of our own here. Which is a low cost rocket that’s the result of a radical systems simplification. We also operate a private space port– our space port is in the Kingdom of Tonga.

[Sandy] Ah, the Tonga one! Why Tonga, other than its location on the equator?

[Randa] As you mention, it’s perfect geographically, and we have friends in Tonga. It’s a place that really really looks delicious in many problems, in terms of space launch. And if you look at what it costs to launch out of a federal space port, or the national space port at any major country, it’s many millions of dollars. And when you’re launching a rocket that costs a fraction of that, how do you actually achieve affordable space launch for clear customers if you’re burdened with these other incidental costs? Plus you’re thrown into a launch rotation that could keep you waiting for years to do launch. And in our case, we’ll be able to do launch on demand, we found out that was absolutely essential, that was an essential component. We first looked at ocean launching, that was another option for us, but we’re doing land launches from Tonga starting, as I said, this year.

[Sandy] Now the joke was that no rocket in the US launches until there’s a stack of paperwork equal to its height. Is that something that Tonga manages to let you escape, either due to governance or even just geography and reduced liability?

[Randa] Well, we don’t escape the paperwork because, as US citizens, we have to launch under a US launch license. And actually we’re going into Washington to begin, let us say officially begin the process of getting the orbital launch license, and that’s be sometime in April. So, in terms of liability, the AST [FAA's Office of Commercial Space Transportation] likes our concept of launching in low populated zones, like the ocean.

[Sandy] I’m told that the biggest advantage of ocean launch is, without any industry or people to worry about damaging…

[Randa] Exactly. It makes your problem simpler. It’s very popular…

[Sandy] Well, fundamental risk is lower, it’s not just the insurance impression on it.

[Randa] Yes, that’s exactly right, no population centers no big infrastructures.

[Sandy] I just don’t want to seem like we’re preying on the third world here. The risks are genuinely lower, it’s not that they don’t charge for it.

[Randa] That’s not even the case. We like the idea of also having a spaceport in a resort, and for us something exotic in the South Pacific is very very exciting. Our kind of a tag line on that is, “from paradise to outer space”. We’re strictly interested in orbital launch, I mentioned that you before, there are suborbital programs and orbital programs. We are strictly orbital and interplanetary. The only suborbital things we do are basically to test our components.

[Sandy] So it’s orbital, then the moon, then planets?

[Randa] Yes, I think it’s low earth orbit, then the moon.

[Sandy] So you mentioned the resort, if I want to head on out for the first TubeSat launch, are you folks going to be able to help me make the hotel bookings then?

[Randa] (laughs) I’ll tell you that it’s a remote area, so be prepared to rough it!

[Sandy] Excellent, sounds like fun.

[Randa] Roughing it in a tropical sense is a good idea.

[Sandy] To wrap it up, say you’re in a noisy pub and someone comes up to you and says ‘what do you do?’, what’s your quick answer to impress them?

[Randa] I run a rocket company. That’s it… it’s impressive to me!

[Sandy] And where do you want to be in 10 years?

[Randa] Oh, maybe Titan? We often talk about the fact that, if we actually get to the point where we’re doing atomic rockets– which is actually our goal– single stage to Titan will be a reality. So for us we have long-term, far-ranging goals.

[Sandy] Well, thank you very much for your time!

[Randa] Thank you, Sandy, and good luck with the TubeSat, we’re waiting to hear that ‘music from space’.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: The Great Millimeter Telescope at Sierra Negra in Mexico

Podcaster: The Great Millimeter Telescope at Sierra Negra in Mexico

Description: The “Gran Telescopio Milimétrico” (GTM for short), built in México, is nowadays the largest and most powerful radio-telescope of its kind in the world. It operates at wavelengths as short as 1mm, it will allow to probe the early universe to study the processes which ultimately formed the galaxies, stars, and planets that we observe today.

Organization: Pleiades. Research and Astronomical Studies A.C. www.pleiades.org.mx (web site soon to be presented also in English)

Bio: Edgardo Molina. B.S. in Mechanical Engineering from the Anahuac University in Mexico City. Post graduate studies in IT Engineering and a Masters Degree in IT Engineering. Working for IPTEL, an IT firm delivering solutions to enterprises since 1998. Space exploration enthusiast who participated in several Mexican space related activities. Licensed amateur radio operator with call sign XE1XUS. Amateur astronomer since childhood and actual founder and president of the Pleiades. Research and Astronomical Studies A.C. in Mexico City, Mexico. Avid visual observer and astrophotography fan. Public reach through education in exact sciences, engineering and astronomy. Lectures and teaching in several universities since 1993.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Elizabeth Fracek, and dedicated to Linda Dunham, my 11th grade science teacher, who taught me more about the universe than anyone else did.

Additional sponsorship for this episode of 365 Days of Astronomy has been provided by Kylie Sturgess and the Token Skeptic podcast, a weekly show about superstition, science and why we believe – at www.tokenskeptic.org.

Transcript:

Hello. This is your host Edgardo Molina from Pleiades. Research and Astronomical Studies in Mexico City, Mexico. We will be talking a little bit on one of the most recent radio-astronomical projects in Mexico. The Great Millimeter Telescope. Thank you for joining us for this episode of the 365 Days of Astronomy Podcast. We hope you will enjoy the show.

The “Gran Telescopio Milimétrico” (GTM for short), built in México, is nowadays the largest and most powerful telescope of its kind in the world. It operates at wavelengths as short as 1mm, it will allow to probe the early universe to study the processes which ultimately formed the galaxies, stars, and planets that we observe today. GTM has been designed and constructed by a joint venture between The University of Massachusetts Amherst in the United States and by the Instituto Nacional de Astrofísica, Óptica y Electrónica
in México.

The GTM includes a single, extremely high precision alt-azimuth antenna which measures 50 meters in diameter. It is located at an altitude of 4580 m above sea level on an extinct volcano, the Tliltépetl, within the National Park Pico de Orizaba, about 100 km east of the city of Puebla and to the west of the Gulf of México.

The GTM is the largest scientific project ever undertaken in México in any field. The national development of novel technologies was set as a requirement for approving the project, a test in itself of the capabilities of México to construct large and sophisticated scientific instruments.

Why are observations at mm wavelengths important? Much of the material in the universe is in “dust” or “grains”, too cold to radiate at wavelengths shorter than the mm/submm range, and so only observable in emission at these longer wave-lengths.

Moreover, the dust in the Milky Way and other spiral galaxies is concentrated in the clouds where new stars form, and it obscures the most interesting interior regions of these clouds at optical, ultraviolet, and even infrared wavelengths. However, it is transparent at mm wavelengths, since the dust grain dimensions are smaller than this. The dust is concentrated in the plane of a typical spiral galaxy. Much of the ultraviolet and visible radiation emitted by young stars is absorbed by dust and re-radiated in the infrared.

Galaxies that are forming massive stars or that contain active galactic nuclei (AGN), presumably powered by super massive black holes, emit the bulk of their energy in the mid and far infrared. But the expansion of the universe shifts this emission for very distant galaxies into the millimeter and submillimeter range. onsequently,
one of the major research areas for the GTM will be the study of the early universe and the origin of the structures that became galaxies, stars, and planets.

GTM is an open-air telescope with no radome enclosure. Much of the improvement over existing telescopes can be obtained with an open loop active surface that includes 180 moveable surface segments. In each segment eight sandwiches of electroformed nickel are supported by a very stiff reaction structure, which is attached to the reflector back structure by a space frame: a 1440 ensemble of such panels.

Four actuators can adjust each space frame in relation to the back structure to correct for deformations due to gravity, thermal gradients and wind. Temperature sensors on all relevant parts of the structure will report to the control system, and the surface will be periodically measured by holographic techniques. Simulations indicate that the GTM should be able to maintain surface accuracy in the presence of winds up to 10 m/s.

The GTM will produce definitive descriptions of massive cores in the interstellar medium of the Milky Way. Mapping of the thermal dust continuum emission with the AzTEC and SPEED bolometer arrays will reveal the column density distribution of material and identify protostellar objects within the massive cores. The local
dynamics and chemistry of the massive core will be determined by imaging of spectral line emission that directly traces the dense gas. Such measurements will define the coupling of the dynamics to the protostellar condensation.

The high sensitivity, angular resolution, and mapping speed of the GTM will enable detailed investigations of the chemistry of interstellar molecular clouds, protoplanetary disks, and comets. The mapping speed of the GTM will allow detailed comparisons of the chemical content of a variety of molecular clouds in differing stages of evolution and with differing physical conditions and environments. Likewise, the high spectral resolution and sensitivity available with the GTM will produce data on isotopic fractionation and its dependence on cloud physical parameters and evolution. Such results will address the relative importance of purely gas phase versus grain surface synthesis of complex molecules in the Interstellar Medium (ISM), and the relation between interstellar molecules, the chemistry of primitive solar system bodies such as comets, the delivery of organic molecules to the early Earth from space, and the role of such molecules in the origin of life.

The GTM is an important station in the millimeter Very Long Baseline Interferometry (VLBI) network as it provides a large collecting area at 1 and 3mm bands and a valuable north-south baseline connecting with Atacama Large Milimeter Array (ALMA). Its participation in the millimeter VLBI campaigns is critical to efforts to resolve the event horizon of the SgrA* Super Massive Black Hole, to reveal shadowing generated by orbiting or infalling plasma, and to measure the spin of the Super Massive Black Hole from flaring events.

The terrestrial planets, planetary satellites, asteroids, and comets have all proved to be fruitful objects for study by radar astronomy. In addition, radar measurements of Near Earth Objects would provide distance and velocity data vastly more accurate than that available from optical images, a critical consideration for the protection of Earth from potentially impacting asteroids and comets.

This is a truly unique combined effort that clearly shows what a good coordination between international institutions can achieve. On the next podcast I will give you more information on other proyects that are currently taking place here in Mexico. There are just too many reasons for this great land and it’s people to pursue a brilliant future, particularly when there is a will to reach for the stars!

Before closing this podcast I would like to send all my respects and appreciation to all the team members
behind the GTM, who kindly posted this and other information online for the people interested in this
exciting project and for you people listening every day to this enthusiastic podcast.

For the 365 Days of Astronomy Podcast, this is Edgardo Molina, from Pleiades. Research and Astronomical Studies in Mexico City, Mexico wishing you enjoy the upcoming summer star party season. Thank you for listening.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: Hayabusa

Podcaster: Steve Nerlich

Description: A brief history of the seven year mission of the little spacecraft that could Hyabusa – before the final step in its mission, scheduled for 13 June 2010 (2pm UTC).

Bio: Cheap Astronomy offers an educational website where cost isn’t an issue, it’s an event horizon. Cheap Astronomy – www.cheapastro.com

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Philip King in appreciation of the staff and volunteers at SolarAid, whose innovative work is bringing clean, safe, renewable solar power to the world’s poorest people, enabling better education and improving health in rural East Africa. Find out more about SolarAid at www.solar-aid.org.

Additional sponsorship for this episode of 365 Days of Astronomy has been provided by Kylie Sturgess and the Token Skeptic podcast, a weekly show about superstition, science and why we believe – at www.tokenskeptic.org.

Transcript:

Hi this is Steve Nerlich from Cheap Astronomy www.cheapastro.com and this is Hyabusa.

Well folks I booked the 10th of June so I could give you a few days advance notice that Hyabusa, Japanese for peregrine falcon, is due to drop its sample return canister at 2pm Greenwich mean time, or coordinated universal time for all you astronomers out there, on Sunday the 13th of June 2010. Unofficially titled, the little spacecraft that could, Hyabusa has had its fair share of trials and tribulations over its seven year mission so perhaps it’s best to say I really, really hope it’s going to land its sample return canister on Sunday.

Hyabusa is an ion drive spacecraft mission led by the Japanese Aerospace Exploration Agency – or JAXA – launched in May 2003 to the asteroid Itokawa which it sort of almost landed on in November 2005.

Now Itokawa, fully titled 25143 Itokawa because it was named by an astronomer, is variously a near Earth object or NEO, an Apollo asteroid meaning its one of a group of asteroids whose orbits cross Earths and have an orbit bigger than Earth’s – and they’re called Apollo asteroids, because the first one ever found was named Apollo – or sorry 1862 Apollo, because… you know.

In fact, Itokawa’s solar orbit is so big enough that it also crosses Mars’ orbit – so additionally it’s also called a Mars crosser – as well as an Earth crosser. Furthermore, it’s also an S-type asteroid, meaning it’s thought to be siliceous, meaning it’s primarily comprised of silicates. So, it’s just a big rock really – while the more common C-type asteroids are carbonaceous, meaning they are more like a dried clay with organic compounds mixed in.

Itokawa is estimated to have a surface gravity of only about one ten thousandth that of Earth with an escape velocity of about 20cm/sec – which isn’t all that much. A good sneeze would probably put you in orbit – although sneezing into your space helmet won’t really work – and opening your space helmet just to see if you can sneeze yourself into orbit means you may not be the sort of person the astronaut office is really looking for.

Anyhow, back to Hyabusa. A long list of misfortunes began soon after its 2003 launch when one of its four ion thrusters failed. Then still not long after leaving Earth a large solar flare burnt out some of Hyabusa’s solar panels meaning its remaining ion drive thrusters’ electromagnets could not be run at full power. This added three months to its travel time to Itokawa and left much less time available for interaction with the asteroid, so the planned landings were reduced from three to two.

Just a few months out from Itokawa, Hyabusa’s reaction wheels failed. These are electrically powered flywheels – and enable the spacecraft to change its orientation in space using gyroscopic forces. With the reaction wheels gone the spacecraft could only rely on its thrusters to turn the spacecraft which was less effective and burnt more fuel. But OK, the mission was still feasible – and every mission has a few glitches, right?

On its arrival to Itokawa in September 2005 one of the two planned landing sites was found to be too rocky to consider landing leaving only one site remaining. But before the landing was attempted, the MINERVA space hopper was deployed – a small probe with a gyroscopic flywheel of it’s own which made it kind of hop along the surface of a low gravity object like Itokawa, so that it could make detailed observations of the asteroid’s surface.

But… because of the radio delay between Earth and Itokawa, Hyabusa had been built with all these automated mission rescue protocols, including an Oh my God, I’m on collision course protocol which unexpectedly kicked in when the spacecraft was about 40 meters from the asteroid’s surface. As a consequence, the spacecraft was already autonomously moving itself away from the asteroid before the command came from Earth to release the MINERVA hopper. The hopper deployed and just drifted off into space, too far away to be captured by Itokawa’s weak gravity field.

Undaunted, on November the 19th 2005, an attempt was made to touch down Hyabusa on the surface – and it was successful (woo hoo) – although communications blacked out when it was about 10 meters from the surface and were only re-established when the spacecraft was found to be nearly 100 meters from the surface, spinning aimlessly in its pre-programmed ‘safe’ mode. It took four days for JAXA to determine from telemetry data that the craft had in fact landed, before its automated Oh my God, I’m on collision course protocol had kicked in – again.

A second attempt to land, this time to collect a sample, was conducted on the 25th of November 2005. A similar level of chaos ensuedand the planned firing of small metallic projectiles intended to throw up dust that would then be taken up by Hyabusa’s so-called collection horn was not recorded in the telemetry data – and it’s most likely that the projectile firing just didn’t happen. However, the sample collection door was certainly opened and then closed again, so the hope is that at least a few grains of asteroid dust may have drifted into the collection horn while it was that close to the Itokawa’s surface.

In any case, with two semi-successful touchdowns on Itokawa, it was time for Hyabusa to return to Earth – and it’s about then that its problems really started. Towards the end of 2005, it became apparent that something was amiss with Hyabusa’s propulsion system and it appeared to have a steady fuel leak, making it difficult to keep it on course. In December, the spacecraft had a sudden attitude change, probably due to out-gassing from a new fuel leak and the spacecraft was turned to an orientation where it could no longer communicate with Earth.

A long period of radio silence followed until March 2006, as the spacecraft passively stabilized back into line so that JAXA could regain control. It took until June 2006 for JAXA to confirm that two of Hyabusa’s four thrusters were still working – just enough to commence the return to Earth on the 25th of April 2006. In August 2006, another of Hyabusa’s thrusters was successfully reignited so that it had three working thrusters, although in November 2009, one of the earlier working ones failed. So, that just as it was about to line itself up for a return to Earth, once again it was back to just having two of four working thrusters and no other attitude control systems available to modify its trajectory.

But with a bit of jiggery pokery – sorry for the technical jargon there – JAXA were able to generate just enough delta V for a proper Trajectory Correction Maneuver – TCM 0 in April 2010.

From there things really started coming together as TCM 1 was successful in May 2010 to get Hyabusa on an Earth re-entry trajectory, followed by TCM 2 on the 22nd of May to tighten that line up a bit further.

TCM 3 on the 6th of June, which will happen just after I record this, will put the spacecraft on line with the Woomera South Australia landing site – and TCM 4 on the 10th of June – that’s today for you folks – will be the very last course correction before the sample return canister separates from Hyabusa on June the 13th and lands at Woomera, South Australia – 3 hours later at 2pm UTC.

As for Hyabusa, the 510 kg mother ship – having successfully brought its sample return canister through a such a fraught filled journey back to Earth – will become a briefly bright artificial meteor on the 13th of June 2010 – the last noble gasp of this plucky little Japanese spacecraft that could, at the very end of its amazing seven year mission.

Thanks for listening. This is Steve Nerlich from Cheap Astronomy, www.cheapastro.com. Cheap Astronomy offers an educational website where we’re happy to sit back and let smart people in space agencies do all the hard work. No ads, no profit, just good science. Bye.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: AAVSONet: An Interview with Dr. Arne Henden

Podcaster: Slacker Astronomy

Description: Mike Simonsen from Slacker Astronomy interviews Arne Henden, the Director of the AAVSO, about AAVSONet, a new global, automated research telescope network created and operated by the AAVSO.

Bio: Slacker Astronomy is a light-hearted podcast that wanders the astronomical road-less-traveled. Visit us at http://www.slackerastronomy.org/.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Kylie Sturgess and the Token Skeptic podcast, a weekly show about superstition, science and why we believe – at www.tokenskeptic.org.

Transcript:

Michael Koppelman: Welcome back! It’s us again, the slackers from Slacker Astronomy here with a podcast for the 365 Days of Astronomy podcast. I’m here with Doug Welch.

Doug Welch: Surprise!! It’s the same year [laughter] and we’re back.

Michael: And Mike Simonson.

Mike Simonson: It’s summertime. I’d rather be slackin’ [laughter]. What are we doin’ dude?

Doug: Sounds like southern time in the northern hemisphere.

Michael: We have to keep telling ourselves that.

Doug: You forget the global reach of Slacker Astronomy.

Michael: The multi-hemisphere of global00.42 reach. Anyway, we’re back again. We have another great short Slacker astronomy-style episode for you today.

Once again Mike Simonson is out there scurrying around interviewing people.

Mike: [Laughter] Scurrying, you make me sound like some sort of rat or something.

Michael: You do have a bit of a scurry toward a thing if you ask me. Today we’re talking about telescopes – automated telescopes taking pictures every clear night of the sky.

It’s called AAVSONet. We’re talking to Dr. Arne Henden of the AAVSO. Mike, what is AAVSONet in one sentence?

Mike: It is a network of robotic telescopes that the AAVSO is developing.

Michael: Doug, do you have maybe two sentences of why that’s cool?

Doug: Well, it’s a very cool thing for people who want to be studying certain stars and their membership in AAVSO allows them to really schedule these observations at no additional cost.

They’re actually beautifully calibrated on really world-class photometry. Arne is one of the best photometrists in the world and so you know your data is going to be really first rate.
Michael: So as Doug just said AAVSONet is something AAVSO members get to use. It is telescopes you can sort of use and get data from; it is free and sort of included.

The guy we’re going to talk to is sort of the brains behind the whole outfit in terms of how they take pictures and how that data eventually makes it to you. Let’s give it a listen.

This is Mike Simonson talking to Dr. Arne Hendon about AAVSONet.

Mike: We’re back again. I’m at the headquarters of the AAVSO. This time I’m talking with Arne Hendon, the director of the AAVSO. We’re going to talk about robotic telescopes. AAVSO now has robotic telescopes.

In fact we have a whole network called AAVSONet. Why don’t you tell us about the telescopes and equipment and where they’re located and some of the sketch details.

Dr. Arne Hendon: AAVSONet was born with a conversation that I had at a Society for Astronomical Sciences meeting in 2005, not long after I became director of the AAVSO. John Gross had a robotic telescope in southern Arizona at Sonoita. He and Walt Cooney and Dirk Terrell were running the telescope.

They wanted to ask the AAVSO to join them as a partner because, first of all these things are efficient. They had extra time sitting available on the telescope and they also thought that my expertise in photometry and so on would be valuable in getting the telescope up and running, making it even better. That was the basis for the network.

We saw that it was fairly easy to do with modern telescopes and commercial software. We then expanded and started bringing in other telescopes into the network. Most of them currently are in the southwestern United States but we are expanding beyond that.

Mike: So you have how many telescopes running right now?

Arne: Right now there are five telescopes that are up and running as of the time that we’re speaking. We have about another five or so that will be coming up in the next year.

Mike: Some of these telescopes are being used for a specific task like APASS. Others are available for AAVSO members to do their own projects. Why don’t we start with APASS first.

Tell us what APASS is – what it stands for – and then we’ll talk about the other telescopes.

Arne: APASS stands for the AAVSO photometric all-sky survey. It is a project that I’ve wanted to do for many decades. If you go back and look at my career in addition to research scientist, I’ve been doing calibration of star fields for many researchers because I’ve gained the experience and ability to do this.

I went back and looked and realized that I was calibrating about ten square degrees per year with a relatively large telescope but small field of view. It was taking me about one hundred nights per year to do this.

If you then extrapolate that to the entire sky, I would have to be at it for 4,000 years. I figured that I [laughter] wasn’t going to be around that long and actually I was getting kind of tired of this and the logical idea to well “can you do this to the entire sky with some sort of a sophisticated system”?

Certainly groups like Pan-STARRS and SkyMapper and SDSS and so on have done it with hundred million dollar class telescopes. But with the telescopes in CCD cameras that were available only a few years ago, we found that we could do a reasonable survey with something far less expensive.

Mike: So this is a photometric survey where you’re actually measuring the brightnesses and colors of stars to a high degree of precision. That’s what you mean when you say calibrating the field.

Arne: That’s right.

Mike: So you’re calibrating the whole sky.

Arne: That’s right.

Mike: You can’t do it all at once so the first part is to do what, the northern sky and then are you going to have another set of telescopes in the south?

Arne: The intent is to take this telescope that we’re currently running in the north – located in New Mexico – and has been operational for a couple three months now, and even during the New Mexico winter. That is an interesting proposition this year.

As soon as it gets most of the way down in the northern hemisphere sky then we’ll move it to the south and work our way up from the south and try to cover the entire sky.

We do have an NSF proposal in that if accepted would fund a second one of these systems and we don’t have to move it and we can actually do it a little bit faster.

It is an entire sky survey. Five colors covering kind of the magnitude range that you would have with an amateur telescope. It seems to have a lot of applications.

Mike: So the sweet spot is like about tenth magnitude to about seventeenth magnitude?

Arne: That’s right.

Mike: Then there’ll be comparison stars for people that are chasing asteroids or comets or variable stars for the whole sky eventually that can be had out of this catalog.

Arne: That is correct.

Mike: As well as other uses of course. We’re mostly concerned with spherical stars and stuff. [Laughter] You also have the bright star monitor. This is a little tiny telescope. What is its purpose?

Arne: It’s kind of funny, when I was the amateur my first telescope was a 2.4 inch (I can’t remember the model number) but anyway, it was a dime-store telescope. So, 60mm, 2.4 inch and I worked my way up to the sort of 6, 7 and 8 meter class telescopes.

Now I’m back down to the 60mm telescope. [Laughter] The reason for this was we were looking at surveys and how they were going to influence the AAVSO two or three years ago in the governing council meetings. We realized that there were gaps in the way that the surveys were covering things. The biggest gap was that none of the surveys was covering bright stars.

There are about a thousand known nice variable stars that are sort of naked-eye and maybe a little bit fainter (small binocular) that just aren’t being covered by any of the surveys.

I said well, I can do this with some small telescope and some of the council members took me to task on that and said: “here’s some money, go do it”. So we designed a small telescope and found a relatively inexpensive mount and we found a way to put this up in New Mexico and it’s up and running.

Mike: Does it just do specific stars? Is it on like a specific program? It’s not like a survey telescope doing the whole sky; it does specific fields each night?

Arne: Well, it is a survey telescope in the sense that it does every known variable in the sky within a certain brightness range; basically, anything brighter than eighth magnitude.

It doesn’t do it by covering the entire sky. It does it by pointing to each of the fields. So we get about 300 stars per night off of that system.

Mike: How big is the field of view on that telescope?

Arne: It is about two and a quarter degrees by one and a half degrees.

Mike: So, it is big but not as big as taking a 50 mm camera out.

Arne: Right.

Michael: And we have to end it there. But like I said there’s more over at slackerastronomy.org come check it out.

And Michael Simonson in the interest of full-disclosure, Arne is your boss, is he not?

Mike: Yes he is. And I am his boss. [Laughter]

Michael: To make matters worse.

Doug: It is the same sort of thing you’ve been watching on Wall Street the last couple of years.

Mike: With a few less orders of magnitude.

Doug: Much less money involved.

Michael: Anyway, AAVSONet – you can check it out at aavso.org and follow links from there. You can use it if you’re an AAVSO member. Being an AAVSO member is easy, not very expensive and it brings you into a hundred plus year-long tradition of observing variable stars as citizen scientists.

Go check it out. We are Slacker astronomy – slackerastronomy.org come say hi. Let’s say good-bye.

Doug: Bye again.

Mike: Good bye for now.

Michael: Adios.

This transcript is not an exact match to the audio file. It has been edited for clarity. Transcription and editing by Cindy Leonard.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: Mysterious Moon Rocks

Podcaster: NASA Lunar Science Institute

Organization: NASA Lunar Science Institute (NLSI) – http://lunarscience.arc.nasa.gov/

Description: Using data from NASA’s Moon Mineralogy Mapper (M3) on India’s Chandrayaan-1 spacecraft, teams of researchers recently found two new kinds of Moon rocks: one was “hidden” on the far side of the Moon, the other has been hiding in plain sight.

Music: “Aquaspheres” from Dr. Sounds, from Magnatune

Bio: The NLSI brings together leading lunar scientists from around the world to further NASA lunar science and exploration.

Nancy Atkinson is a science journalist and is the Senior Editor for Universe Today.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by Graham Hewett “For my wife Cecilia who puts up with all the geeky things I do.”

Transcript:

Voice: You are listening to the NASA Lunar Science Institute podcast which highlights the latest news information of the Moon, on the Moon and from the Moon. It is produced from the NASA Lunar Science Institute at the Ames Research Center in Moffett Field, California.

Nancy Atkinson: There’s a mystery on the Moon! Hi, this is Nancy Atkinson for the NASA Lunar Science Institute. Thanks to the Moon Mineralogy Mapper instrument or M cubed, on the Chandrayann-1 spacecraft, scientists have found two different kinds of never-before-seen lunar rocks – one kind on the far side of the Moon and the other staring right at us on the near side. The composition and location of these new rock types are puzzling lunar scientists. To learn more about these mysterious Moon rocks, we talked with Dr. Carle Pieters from Brown University who is the Principal Investigator for M cubed as well as Dr. Jessica Sunshine from the University of Maryland, a co- investigator with the project.

Dr. Pieters tells us about the newly found rocks on the far side.

Dr. Carle Pieters: The rock type on the far side of the Moon that is so unusual is a magnesium spinel lithology. Now, what that means is that there is a mineral called spinel that is typically an iron, magnesium, aluminum oxide. The particular kind of this mineral that we found is a magnesium end member with a little bit of iron in it. Which is called basically a spinel, a normal definition of a spinel. So that’s the mineral specifically. Now what’s unusual about the minerals that we found on the far side is that the general geology of this particular area is common on the moon. It’s class of crater that are called basins, these are over 300 km in diameter, so they are huge! It’s a big hole in the ground that was formed early in lunar history about 4 billion years ago. We don’t know the exact dates, but we know they were early. This period ended about 3.8 billion years ago. The Moon’s surface is peppered by these major basins. Now, what we normally see when we look at this particular basin on the far side, it’s the Moscoviense Basin on the far side. It’s a very, quite typical wonderful basin on the far side of the Moon that has excavated quite normal plagioclase rich lithology, which was later filled with basaltic rich mare lavas. So it is quite a typical large basin in terms of all the compositional properties we have measured.

But what we noticed by looking in detail at the spectral properties of the material, and in particular the material along the inner-most ring of this basin, which has mostly likely exposed the deepest materials from the crust, we noticed there were a few little areas that were unusual – spectroscopically unusual. So, of course we investigated those in more detail. And found that these unusual areas had a whole list of properties that were quite perplexing. First of all they were unusual, but not unusual in the same way. There are three primary different compositions and two we had seen elsewhere, although not at this particular location, and these are compositions that are rich in iron bearing minerals called pyroxene and olivine and so we see small areas of these pyroxenes and olivines and we say ‘Hmm, that’s interesting!’

They are widely separated, and that was a mystery in itself. But then the third kind of mineral we had never seen before, and what is interesting is not only is there an unusual abundance of this particular mineral, but it also has a lack, an absence of the minerals that we are more familiar with, the pyroxenes and olivines that we see elsewhere. So there are several mysteries that are interwoven here. One is why do we have a concentration of this spinel mineral and however it got concentrated in this area, why aren’t the other minerals that we are familiar with also there, because they are not. So this is a big mystery and it is a very exciting one because now we have to reexamine our understanding of the character of the lunar crust, in particular to the depths that might have been tapped by this enormous basin and that we are now looking at exposed on the surface.

Nancy: Dr. Pieters said there is also a related question about this region on the Moon.

Pieters: Not only are these unusual areas, and they are only about a kilometer or two in size, unusual compositionally, but in every method we’ve been able to look at thus far, in every wavelength and resolution, they have no other distinguishing properties. Typically, on the Moon to indentify an usual composition we look for a fresh crater that has excavated and exposed material on the surface of the Moon. These areas have no fresh craters, no disturbance at all across their surface, even at the highest resolution that is seen with the LROC (Lunar Reconnaissance Orbiter Camera) instrument which measures a half a meter resolution. These are old surfaces that have been undisturbed but have an extremely unusual composition. And even the space weathering that has occurred on the surface throughout the billions of years of history on the Moon has not erased their unusual compositions. So, they are unusual for the kind of compositions we see, but they are also unusual because they have no identifying property that allows us to identify them in our imagery which is quite unusual for features on the surface of the Moon.

Nancy: Now let’s move to the near side of the Moon, where Dr. Sunshine was given a specific task.

Dr. Jessica Sunshine: One of the things I was asked to be in charge of was looking for anomalies, things that just didn’t look like the rest of the Moon. And of course you never know what’s going to happen under those circumstances. Carle had already discovered that there seemed to be some magnesium spinel on the far side of the Moon and I went looking to see where else it was, and found that the only place that we had anything that looked like the spinel mineral in data we had at the time was on the near side and it was an extremely large deposit in the middle of the central nearside, almost exactly dead center at zero zero. And we started looking a little more carefully and realized that it wasn’t really the same kinds of things that Carle found, which truly was a new rock type on the far side of the Moon, but something usual about the regions that we had already known was full of what we call dark mantle deposits or pyroclastic deposits, which is firefountaining deposits, which we have going on in Iceland right now. We have lava and gas, explosive eruptions over large areas of the Moon, about the size of Massachusetts. And we knew that three of them were there, it just turned out that one fo them was compositionally different from the other ones, and in particular it had the kind of spinel which is a chromite, because it has chrome in it, and now we’re busy trying to figure out why this deposit is different from the one next door, and what does it mean. And we’re still working that process out as we speak.

Nancy: I asked Dr. Sunshine what it’s like to find something new like this on the side of the Moon that humans have looked at for millennia.

Dr. Sunshine: Yeah, I tend to title my talks on the subject something like, “Hidden in Plain Sight” because they are! Its right there and I think this is a really fascinating part of this because we have been starring at the Moon, as humanity for millennia and if our eyes were slightly different we would see this one really dark spot in the middle of the Moon that is different from anywhere else.

Nancy: And these discoveries couldn’t have been made without the Chandrayaan-1 spacecraft and the Mcubed instrument.

Sunshine: Mcubed is able to see, if you will, it collects data over amuch broader range of light than our human eyes can. We can all see the rainbow, we’re all familiar with that, from blue to red, but there is light at shorter wavelengths, which we call ultraviolet, and particularly for this case, there is light at shorter wavelengths called infrared, and Mcubed goes farther into the infrared than humans can see and it is there we are able to see diagnostic fingerprints of different kinds of minerals. So I suspect there are certain kinds of bugs who would look at the Moon and would have known these deposits are there because their vision goes into the infrared!

Nancy: So, Dr. Pieters, does these new discoveries tell us there are still more mysteries to find on the Moon?

Pieters: Oh, absolutely! We’ve just barely scratched the surface here. This is thrilling from a spectroscapist’s point of view, of course, but also from someone who is trying to understand how planets work, and in particular how this wonderful small body in our neighborhood is telling us about the characteristics of crustal evolution and fundamental properties of planetary surfaces.

Voice: To find out more about this topic, visit our website at www.lunarscience.nasa.gov. Any opinions expressed are the individuals and do not necessarily reflect the opinion of NASA or the NASA Lunar Science Institute. This podcast is produced for educational purposes only. On behalf of the NASA Lunar Science Institute, thanks for listening.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.

Title: The 75th Anniversary of the David Dunlap Observatory

Podcaster: Toronto Centre of the Royal Astronomical Society of Canada

Organization: Toronto Centre of the Royal Astronomical Society of Canada www.toronto.rasc.ca.

Description: The David Dunlap Observatory celebrates its 75th anniversary; also conservation of historic observatories is discussed.

Bio: All of our presenters are council members of the Toronto Centre of the Royal Astronomical Society of Canada.

Karen Mortfield is our public affairs co-ordinator.

Dr. Ralph Chou is the president, and also a professor at the University of Waterloo school of optometry.
Brenda Shaw is a councillor and one of our volunteers at the David Dunlap Observatory.

Eric Briggs is the secretary of the Toronto Centre and also a contractor with the Spitz planetarium company.

The Toronto Centre of the RASC is grateful for the assistance we’ve received from Metrus Developments and the Town of Richmond Hill, Ontario.
You can find out more about the David Dunlap Observatory, its history, and our 2010 schedule of events at our website, www.theddo.ca.
The RASC Toronto Centre’s website is www.toronto.rasc.ca.

Today’s sponsor: This episode of “365 Days of Astronomy” is sponsored by orbitalmaneuvers.com. “Orbital Maneuvers”, the new sci-fi thriller by RC Davison is now available online at Createspace.com and Amazon.com. Follow the crew of the space shuttle Endeavour as they struggle to survive the effects of a devastating asteroid impact on the United States, which leaves them stranded in orbit. Shuttle commander, Susan Corin, must not only contend with the aftermath of the disaster and a damaged shuttle, but must deal with a crew member whose homicidal actions to save himself have put the rest of the crew in grave danger. Check out the companion website where you can read the first 7 chapters of the book, read background information about the space shuttle, the International Space Station, asteroid impacts and more. There are also links available to order the book online. Thanks to 365 Days of Astronomy for all their hard work in making a website about astronomy that is literally for the people, by the people!

Transcript:

May 31, 2010 celebrates the 75th anniversary of the David Dunlap Observatory in Richmond Hill, Ontario, Canada, located just north of Toronto. At the time it opened on May 31, 1935 it was the 2nd largest in the world, and the 74-inch diameter telescope remains the largest optical telescope in Canada.

The existence of the David Dunlap Observatory is largely due to the efforts of one man, Clarence Chant. Professor Chant campaigned for the better part of thirty years for a large observatory near Toronto. The existence of the Royal Astronomical Society of Canada is also largely due to Professor Chant. David Dunlap was a wealthy member of the Society, and after his death Professor Chant met with Mrs. Dunlap, who agreed to fund the observatory as a memorial to her husband.

The 74-inch telescope was manufactured by the Grubb-Parsons company in England. The Parsons part of the company comes from Charles Parsons, whose father was the Earl of Rosse in Ireland, who built a 72-inch telescope in the mid-19th Century called the Leviathan of Parsonstown, that was the largest telescope in the world for decades. The telescope mirror for the DDO was manufactured by the Corning Glass Company in New York, as a test article for the larger 200-inch mirror for Palomar Mountain that was made a short time later. So the DDO was built by the best.

The spectrograph at the DDO was used to independently confirm the first Black Hole, Cygnus X-1 in 1972. That’s the most well-known accomplishment of the DDO, but many other research projects have been conducted here. For example, studies of how Polaris varies its brightness. The first blazar, BL Lacertae, was co-discovered by astronomers at DDO. Helen Sawyer Hogg discovered a nova in the globular cluster Messier 14 on photographic plates she exposed at DDO, in the process of a long project to determine the distances to globular clusters to determine the scale of the universe. Astronomers trained at DDO went on to do good work elsewhere. For example, Dr. Wendy Freedman and Barry Madore, (Wendy is the director of the Observatories of the Carnegie Institution) both did their first astronomical work at the DDO.

What happened at the Dunlap Observatory is that the University of Toronto found that most of their astronomy faculty were doing work away from the observatory they owned. The University had another observatory on Cerro (See-Arrow) Las Campanas in Chile for a while, but nowadays some of their astronomers are using the much bigger Canada-France-Hawaii Telescope, Hubble Space Telescope, the Gemini telescopes and so on. Also, the urban areas around the City of Toronto have grown up around the observatory and although some pioneering work has been done to reduce the impact of light pollution, the DDO is not a dark sky site any more. Rather than leasing the observatory to a community group themselves, the U of T sold the Dunlap Observatory property to a developer, who has since leased the observatory dome back to the Toronto Centre of the Royal Astronomical Society of Canada – that’s us. The University then used the proceeds from the sale to start a new Dunlap Institute for Astrophysics, which is expected to be a centre for cutting-edge science that will continue to work with the world’s largest telescopes. Since purchasing the DDO site, the developer has also participated in a series of consultations with the Town of Richmond Hill and community groups concerned with how they plan to use the rest of the property. We think those consultations are far from over, and we’re glad to have a part to play in the process. In the meantime, we held a successful series of public observatory nights last year, and we’ve begun a new season in 2010.

The Toronto Centre of the Royal Astronomical Society of Canada today is the same kind of organization it was when Clarence Chant helped to bring the Society together a hundred years ago: a combination of amateurs and professional astronomers. Several of our members were trained at the DDO when they were in University, and several more have been trained to operate the telescope during the last year. The RASC has helped operate public astronomy outreach activities at the DDO since it opened 75 years ago, and several of our members have gone on to be on the staff of the observatory over the years, so many of our younger members were inspired to pursue professional astronomy careers. We’re continuing this work, doing science outreach with schools, to communicate astronomy which is part of the provincial school curriculum.

Earlier this year we had a visit from Dean Regas, an astronomer from the Cincinnati Observatory Center. Cincinnati Observatory was originally opened by former President John Quincy Adams in 1843, making their site almost a century older than ours, although their observatory has moved a couple of times since then. The Cincinnati Observatory land is still owned by the University of Cincinnati, but for a while in the 1990s they considered selling the land for development. The Cincinnati Observatory Center came along and leased the observatory from the University, so they saved it. Now it’s used more for public outreach in astronomy than hard research. After meeting us and having a look through our telescope, Dean told us he feels like we’re at the stage he and his friends were at about ten years ago.

One of the other historic observatories we’ve been communicating with is Mount Wilson Observatory near Pasadena. When the DDO was completed in 1935, the telescope here was the second-largest in the world, and the largest was on Mount Wilson. It’s still there, but for several years in the 1980s and early 1990s the 100-inch telescope at Mount Wilson was closed and the funds used to operate it were re-allocated to new telescopes elsewhere by the Carnegie Institution, which used to run Mount Wilson. Within a few years, Carnegie turned operations on the mountaintop over to the Mount Wilson Institute, a 501(c)(3) non-profit corporation. The 100-inch Mount Wilson telescope was brought back into service in 1992, in time to record Comet Shoemaker-Levy 9 colliding with Jupiter. The 100-inch telescope is still used for research projects, but a smaller 60-inch telescope that was built in 1908 is used for public outreach programs. The biggest threat to Mount Wilson is not development; it’s fire. Last year, the Station Fire burned 250 square miles of the forest and communities near the observatory, and the tenacity of the firefighters was the only thing that saved Mount Wilson.

Sometimes historic observatories can’t be saved. Mount Stromlo Observatory in Australia, which has a telescope very similar to the one at the DDO, was overtaken by fire in January 2003, and all of their instrumentation was destroyed. The facilities at Mount Stromlo are being rebuilt, but the 74-inch telescope has been abandoned in place. Mount Stromlo is going to make its future by building instruments and controls for new cutting-edge telescopes like the Giant Magellan Telescope.

There’s another telescope similar to ours in South Africa. Their 74-inch telescope was built near the city of Pretoria in 1948, but after Pretoria grew, their telescope was actually disassembled and moved hundreds of miles across the country to a deserted location, away from light pollution. The move was finished in 1972. It’s really remarkable that a 74-inch telescope like that could be moved. I don’t think it could have been done after South Africa converted to the metric system. The new site has more recently been used for the South African Large Telescope, a giant dome with an 11-metre diameter mirror. Most of the interest in the site now is for the giant telescope, which is one of the two biggest ones in the world. The 74-inch telescope in South Africa is still used every clear night, according to Dr. Ian Glass, the telescope operator there.

The David Dunlap Observatory is close enough to Toronto that light pollution is a problem, but the Town of Richmond Hill’s anti-light-pollution by-law is one of the tools that minimize the impact of development. We have several observing methods that aren’t affected by light pollution, less than an hour’s drive away from 5 million potential astronomers in the Toronto area. We’d like to use the facility to inspire the next generation to wonder about the universe and our place in space and choose careers in science and technology. We have a wonderful new mission for the future that will keep the telescope an active and integral part of the community and Canadian science education.

And if you’re interested in an observatory or a planetarium in your town, go out and show your support. The organizations and universities that fund astronomy in your country are probably interested in funding the most sophisticated astronomical research, the kind that can only be done in space or on remote mountaintops… and who can blame them?! If those funding dollars are being spent on remote observatories in other parts of the world, it’s up to you to work with those funding authorities and landowners to keep operations going at your local astronomy center.

End of podcast:

365 Days of Astronomy
=====================
The 365 Days of Astronomy Podcast is produced by the Astrosphere New Media Association. Audio post-production by Preston Gibson. Bandwidth donated by libsyn.com and wizzard media. Web design by Clockwork Active Media Systems. You may reproduce and distribute this audio for non-commercial purposes. Please consider supporting the podcast with a few dollars (or Euros!). Visit us on the web at 365DaysOfAstronomy.org or email us at info@365DaysOfAstronomy.org. Until tomorrow…goodbye.