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Podcast title	You'd Prefer an Astronaut
Website URL	http://astroshow.blogspot.com/...
Description	Weekly radio show which covers the latest news and views on the cosmos
Updated	Tue, 16 Mar 2010 06:00:06 PDT
Category	Science & Medicine
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Episodes
1. A family portrait http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Of our Solar System. Courtesy of Voyager. E njoy.
2. A Wise comet http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Well, the comet itself probably isn't wise (it isn't alive you know), it was discovered by the recently launched Wise satellite. Go h ere to learn more.
3. The "Burps" of Baby Stars http://feedproxy.google.com/~r... download (, 0.00Mb) Description: As seen in this beautiful image of the Orion Nebula, many of the young stars in this region are ejecting gas of at speeds of several thousands of miles per hour. Why? How? Well, people are still trying to work it out... The pictures are gorgeous though!
4. NASA's new priorities http://feedproxy.google.com/~r... download (, 0.00Mb) Description: As I'm sure many of you have already heard, the proposal 2010 Federal Government budget has major implications of NASA - essentially suggesting that the new Constellation program to replace the space shuttle be scrapped in favor of more basic science satellites. The NY Times has its opinion here, what do you think? I'm curious to know, so please leave your opinion below.
5. The Spectrum of an Exoplanet http://feedproxy.google.com/~r... download (, 0.00Mb) Description: While the first exoplanets (planets orbiting stars other than our own Sun) were first discovered more than a decade ago, the composition of these planets has long remained a mystery - especially since these planets appears to be very different than any planets in our own Solar System. Thanks to the capabilities of the ESO's VLT in Chile, a group of astronomers were able to finally directly measure the spectrum of one of these exoplanets (as opposed to looking at absorption lines which appears with the exoplanet passes between us and its star) - giving vital information on the chemical composition of its atmosphere. Go here for details, and enjoy!
6. Dancing Moons http://feedproxy.google.com/~r... download (, 0.00Mb) Description: In projection, at least. Go here to see what I'm taking about, courtesy of the Cassini team.
7. The Ever-shifting face of Pluto http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Just because it isn't a planet anymore doesn't mean it isn't interesting. Go here to read what some recent Hubble pictures of the founding "plutoid" revealed.
8. Where did spiral galaxies comes from? http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Hubble might have imaged their ancestors, the proto-galaxies which merged together to form spirals like our own Milky Way. And they didn't appear to be spiral-like at all. Go her e for more details.
9. Stars in their cocoon http://feedproxy.google.com/~r... download (, 0.00Mb) Description: As imaged by the Hubble Space Telescope. Go her e to see for yourself.
10. Little telescope... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: ... big exoplanet. Go her e to read how an old, fairly small, NASA-run telescope in Hawaii was able to measure the properties of the atmosphere of a planet in another solar system. Enjoy!
11. Baby massive stars... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Aren't they so cute? Go here to see a recent image of a stellar nursery in the Milky Way, where the most massive star in our galaxy may reside.
12. Asteroid collision? http://feedproxy.google.com/~r... download (, 0.00Mb) Description: You would think, given how "empty" space is, the odds of two asteroids colliding together would practically never happen. However, it appears that Hubble might have imaged the debris from such a collision. Go here for details.
13. Firefly is back!!!! http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Not the TV show, unfortunately. But NASA is planning on launching a new satellite called Firefly to study flashed of gamma-rays - from the Earth! Where they are coming from (no, they are not from underground nuclear tests. Those would be absorbed by the ground and atmosphere and never make it out to space), no one really knows. Read more about it here.
14. Robot Comic http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Th is is pretty awesome, even though I know it has no astronomy content whatsoever. Tom and Servo live!
15. Want to save the Earth? http://feedproxy.google.com/~r... download (, 0.00Mb) Description: It is an astronomical object, after all. Go here to learn more about how you can affect climate control.
16. This Sundog will bark no more http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Not really of any scientific value, but this is just cool. Bad SDO, bad!
17. While we were on the topic... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: The type of supernova (Type Ic) discussed in the press release I posted about yesterday, with direct evidence it formed a black hole, is believed to be associated with Gamma-Ray Bursts. Why some of these supernovae produced gammma-rays and others don't isn't known, but maybe th is result will help clear things up. Maybe. It is still a puzzle...
18. The Origin of Type Ia Supernovae http://feedproxy.google.com/~r... download (, 0.00Mb) Description: As you may have seen, last week a major discovery concerning the nature of Type Ia supernovae which are so important for cosmology. First, why are these supernovae so important? It is because this class of stellar explosions are believed to all be essentially the same - i.e., they all produce the same amount of energy. This means that, if you see one on the sky, you can use its brightness to get its distance (its "luminosity distance" to be overly technical). From its spectrum, you can get its redshift, and by comparing the distance vs. redshift for many of these, one derives the expansion history of the universe. This is pretty much how astronomers first inferred the existence of "dark energy" in the universe, a measurement that is supported by completely separate techniques which I'm not going to discuss now. Okay, so what are these explosions? That has been the tricky part. Based on their similarity to each other, their optical spectra, how often they occur, and the type of galaxies in which they occur, type Ia supernovae have long been associated with the thermonuclear explosion created by the gravitational collapse of white dwarf. What's that? Well, white dwarfs are "stars" which are supported not by fusion in their core like our Sun, but by the fact that electrons can't get too close to each other ("electron degeneracy pressure"). However, if the mass of the white dwarf is too high, its own gravity is too strong to be balanced by this pressure and it collapses on its self, triggering an explosion which envelopes, burns, and then blows up the entire white dwarf. Since this maximum mass is pretty much the same for all white dwarfs (1.4 Solar Masses, the so-called Chandrasekhar limit since it was first derived by Prof. Chandrasekhar - easily one of the most brilliant astrophysicists of the 20th century and the person that Chandra is named after), it isn't too surprising that Ia supernovae are so similar. Okay, but how does the white dwarf get so much material? There are two possibilities. The first is that a normal star is in a close orbit around the white dwarf. In some cases, the gravitational attraction of the white dwarf will be so strong that is will rip off the outer layers of the normal star and cause this material to fall onto the white dwarf, gaining mass. (This process is generically called "accretion") The second possibility is that two white dwarfs are orbiting each other, merge for whatever reason, and then the combined mass of the two white dwarfs is so high that it explodes. How can you distinguish them? Well, in the first scenario, the material which accretes onto the white dwarf is hot and shines brightly in the X-rays, while in the second scenario you would get no such emission before a Ia supernova. Is this difference actually observable? Looks like it is. To read more, go here and her e among other places. The actual scientific article can be read here, but you might need a library or university IP address to read it for free (any decent public library will have the print version, which is easier to read anyway). Hope this made sense. Please leave questions below.
19. Speaking of stellar-mass black holes... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: ... it turns out that their formation might help their parent explode after all. Black holes as black widows seems fairly fitting, don't you think? Go here to read about it. This is one of the very few times where we actually observed the supernova and measured the properties of the produced compact object - and the first time for the limited set of explosions that it appears a black hole and not a neutron star was produced. Very exciting indeed.
20. A WISE view of the heavens http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Here are the first batch of processed images returned by NASA's WISE satellite, which over the next few months will image the entire sky in the mid-infrared. Pretty, isn't it? And so much science in there too....
21. Why won't Spring hurry up? http://feedproxy.google.com/~r... download (, 0.00Mb) Description: Because it can't, as illustrated by this FoxTrot comic. Of course, in the Southern hemisphere, they are waiting for Fall not Spring.
22. The furthest black hole... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: .. so far. And stellar mass black hole (the ones produced during the death of the most massive stars), not the supermassive black holes believed to be at the center of practically every massive galaxy (in which case, the most distant one is just the most distant galaxy). Go here to learn how it was discovered...
23. California's Climate Educator Conference http://feedproxy.google.com/~r... download (, 0.00Mb) Description: NASA and JPL will be hosting a Climate Educator Conference May 1-2, 2010, not surprisingly, at the Jet Propulsion Laboratory, Pasadena, California. In this conference, JPL and local scientists, geographers and planners will address the current climate, the historical record, long range trends and future forecasts in context. Special attention will be paid to the California science standards, especially key areas like fourth grade where California is a year-long theme. This is intended for all educators (including museum staff) and students (high school and above) interested in earth and space science and exploration. The objective of the conference is to tell the exciting tale of real-life exploration and new discovery in a way that will excite and inspire students. Students under 18 years of age must be accompanied by a registered adult. The bulk of the conference is presentations, not workshop-type activities, but instructional materials and resources will be shared. Pre-registration is required. Walk-up registration will not be possible for this conference. To register for this conference please send a check postmarked by April 26, 2010, for $45.00 payable to "Jet Propulsion Laboratory" to: California Educator Conference Attn: Mary Kay Kuehn Jet Propulsion Laboratory M/S 180-109 4800 Oak Grove Drive Pasadena CA 91109 Please provide the following information: Name_______________________________ Title________________________________ Organization/School_______________________________________ Address________________________________ State___ Zip______ Citizenship_________________________ (Please bring a photo ID) Grade(s) Taught__________________________________________ Subject(s) Taught_________________________________________ Contact info for confirmation & last minute changes: E-mail: _____________________________ Phone: _____________________________ Please register by Monday, April 26, 2010. The $45 registration fee includes continental breakfast and breaks both days and a box lunch on Saturday. For registration questions please call the JPL Education Office at 818-393-0561. For other questions please call the JPL Educator Resource Center at 909-397-4420.
24. ... but Spirit persists http://feedproxy.google.com/~r... download (, 0.00Mb) Description: now as a rover, but a stationary lab. I know I'm more than a little late reporting this (there is a reason why I'm an astronomer and not a journalist), go here and here for more details.
25. WISE's first discovery is... http://feedproxy.google.com/~r... download (, 0.00Mb) Description: ... a near-Earth asteroid. It's good to discovery these things in time, don't you agree? Go h ere to read more how it was identified, and how many more WISE is expected to see.