Thursday was my last day (or really hour) at the American Astronomical Society (AAS) meeting. I went to the morning invited talk, which is usually a great way to figure out what theories, and what scientists, are big in the field right now.
A simplified “longitudinal” map of Earth gives a rough estimate for where landmasses are on our planet. Scientists hope to create such maps from data of earthlike planets, and thus learn if these worlds harbor land. Liz Kruesi photo
Eric Agol of the University of Washington spoke about exoplanets. He focused on one type of detection method, transits, which occur when a planet crosses in front of its star and thus blocks light according to our view. In particular, Agol talked about what astronomers can do with the information they glean through transiting exoplanets.
The newly discovered worlds Kepler-9b and 9c were two main examples of the talk. These planets are in nearly resonant orbits, with one completing two orbits in the time it takes for the other to complete one. But to figure this out, scientists had to carefully analyze the brightness dips caused whenever the planets passed in front of their star.
He also covered ways to analyze atmospheres, and thus weather, on massive exoplanets called “hot Jupiters.” Years ago, astronomers had begun to figure out general information about one such world, HD 189733b — meaning, they could determine that one part of the atmosphere is hotter than another part, and that this is likely due to high-speed winds. (OK, it’s more complicated than that. See February 2010’s article in Astronomy magazine about weather on exoplanets for more information.)
Agol also showed how this research could extend into analysis of earthlike planets. So, to simulate what such a world’s atmosphere might look like, scientists took images in seven filters of our planet using the Deep Impact spacecraft. They then simulated an extremely basic map to provide an idea of landmasses versus oceans (and thus an estimate of the percent of land). Pretty neat.
After this talk was over, I had to head out of the meeting. Today was the last day, so I’m hopeful I didn’t miss too much. AAS meetings are always packed with information — between press conferences, oral presentations, and posters (not to mention the “town hall” meetings and just running into familiar people). You’ll definitely see some articles in future issues of the magazine from topics that came out of this meeting.
Related blogs:
AAS meeting: January 12, 2011
AAS meeting: January 11, 2011
AAS meeting: January 10, 2011
AAS meeting: January 9, 2011