Description of September 10th Radio Show: Milky Way Structure and Galaxy Formation

Already available here, below is a description of the September 10th edition of this radio show. On this program, I discussed:

• Calendar of upcoming Astronomy / science events in the greater Poughkeepsie / New York City area.
• Interview with Prof. Allyson Sheffield of Vassar College.
• News: Phoenix Mars Lander begins analysis on deepest soil sample to date (link) as well as makes some puzzling measurement regarding humidity on the Martian surface; amateur astronomers see Perseid meteor shower hit the Lunar surface; ESA's Rosetta spacecraft flies by astroid (2867) Steins - sees chain of craters, rotation, and overall diamond shape (link); Cassini detects ring arcs around two moons of Saturn (link); NASA awards contract to S.C. Jones Services, Inc. to get rid of pests at Kennedy Space Center; NASA building "Solar Ultraviolet Magnetograph Investigation" to measure the strength of the magnetic field at the outer edges of the Sun; NASA developing a new space equiptment rack for "Zero-Gravity" flights; NASA delays launch of Space Shuttle Atlantis to October 12 and launch of Space Shuttle Endeavor to November 12 due to bad weather - media viewing of equipment to be flown on Atlantis for installation on Hubble Space Telescope set for Sept. 10; launch of ESA's GOCE satellite delayed due to rocket problems; NASA to hold media briefing on September 25th on Lunar Exploration plans; mirror blank produced for Large Synoptic Survey Telescope (link); NASA produces 50th anniversary art book - information here; NASA announces new Carl Sagan postdoctoral fellowship to study extra-solar planets - information here; NASA issues a challenge to high school and college students to describe a future supersonic airliner - information here - as well as a new aeronautics competition - information here; Swift to announce new gamma-ray burst findings today; Custer Institute to host 30th annual Astronomy Jamboree and Conference October 3rd and 4th.
• Milky Way Structure and Galaxy Formation: It is currently believed that all galaxies, including the Milky Way, formed by the merging of smaller galaxies together - an this process is ongoing. If this is correct, there should be evidence for this in the Milky Way today - as discussed by Prof. Sheffield at the beginning of this show. A recent survey of satellite galaxies of the Milky Way, small galaxies which are in the process of merging into our galaxy, discovered that they all have roughly the same total mass (stars + dark matter) - regardless of how many stars they have. This implies something strong about the formation of these galaxies or the properties of dark matter - astronomers are still not sure which (link). Evidence of previous mergers is also in "streams" of stars - stars with similar orbits and chemical composition - in the halo of the Milky Way. There are many questions regarding the structure of the Milky Way - including how many spiral arms there are, since two of the spiral arms that were thought to be there have apparently disappeared (link).

Hope you enjoyed and, as always, any and all feedback is appreciated. Thank you very much for listening!