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.