Wednesday, January 06, 2010

Wrapup of Day 2 of the American Astronomical Society Meeting

Yesterday, day 2 of the 215th meeting of the American Astronomical Society (AAS) was yet another exciting day, with new results from both Earth's backyard and the most distant known reaches of the Universe. Today promises to be another exciting day, starting with space shuttle astronaut, Hubble repairman, and newly-annointed Deputy Director of the Space Telescope Science Institute, John Grunsfeld. I'll be tweeting as time allows, and searching Twitter for #AAS and #AAS215 will get you more astronomy than you can shake a stick at.

Tuesday started with a talk by planetary scientist Maria Zuber. She gave a review of the search for water on Mars, starting with the earliest Mariner probe images that suggested the Red Planet was as dry as the moon to modern studies that suggest Mars has huge reservoirs of water ice just under the surface. None of these results were new announcements, but since few astronomers read a lot about the inner Solar System, many of us learned quite a bit.


The basic story of water on Mars starts with the Tharsis Bulge, a huge accumulation of basalt (lavas like the Hawaiian volcanoes produce) on the surface of Mars. As any of you who've seen volcanic eruptions know, lava is full of gases as well as liquid rock. These gases include carbon dioxide and water vapor. If you assume that Martian lava has the same amount of gases as the Earth, than the lava that made the Tharsis Bulge on Mars released enough water to cover the entire surface of Mars with a 120-meter deep ocean. Since Mars is further from the sun, the planetesimals that melded to form the planet could have contained twice as much water as those that made the Earth, so the lava could have released twice as much water.

For many years, scientists have pointed to surface features on Mars that look like dried rivers and oceans, but those are just circumstantial evidence that water once was on Mars. They don't tell us anything about whether Mars actually had oceans, how long they lasted, and where the water went. However, there is now conclusive evidence that much of Mars has water ice no more than 1 meter below the planet's surface. The Mars Phoenix lander found ice at the Martian poles, and images of brand new craters on Mars show excavated water ice. So, the water is still there and likely quite plentiful. All in all, a very interesting talk.

In the afternoon, I went to a professional development workshop that explored negtiation techniques. While there are a couple of teaching-related development workshops at each AAS meeting, this is the first meeting that had workshops on other professional topics.

I am very happy to see these workshops come to the AAS. Too often we astronomers feel that we don't need formal training, that we can learn what we need on our own. Instead, we end up reinventing the wheel, and that wheel is often more square than round. It's silly not to draw on the accumulated knowledge of business and management. I hope that the AAS continues to support these workshops, and that more astronomers swallow their pride and attend.

Finally, there was a press release on the most distant galaxies ever seen with Hubble. I don't have time to write about that now, but you can read the press release or a news article here.

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