Discarded posters in the near-empty exhibition hall are a sure sign that the American Astronomical Society’s 220th meeting is almost at an end. // photo by Bill Andrews
Another American Astronomical Society (AAS) summer meeting has come and gone. Today’s recap will be a shorter one, because the final day of the meeting has fewer events, and because I have to catch a flight in the afternoon (in order to arrive in Milwaukee tomorrow morning — fun!). So let’s get to it!
The day began, again, with solar science. Jeffrey C. Hall of Lowell Observatory in Flagstaff, Arizona, spoke about “Solar Twins and Stellar Maunder Minima.” The former are, naturally enough, stars that mimic the Sun’s behavior well enough to be considered “twins” — although Hall warned that “we’ll never find an absolute clone of the Sun,” so it’s important not to be too restrictive when searching them out. The latter refers to stars undergoing very little activity, as our local star did from 1650 to 1710. Studying the two are important not just to better understand our Sun and other stellar behavior, but also because they will prove practical in exoplanet studies and finding a true Earth-like planet. Hall also reveled the discipline is beset with an “Augean Stable” of incomplete or hard-to-compare data, so he urged others to help him in his quest to clean up and organize the existing information.
Next, I decided to see a sequel to one of Monday’s events by attending the “Solar Systems II” special session. Again, the topic was planetary science, and this time it was exclusively of the extrasolar variety. One of the first speakers, Thomas Barclay of the NASA Ames Research Center in Moffett Field, California, gave an interesting talk titled “Exploring the Smallest Planet Candidates from Kepler.” Despite having found some pretty tiny candidates — smaller even than Mars — the biggest problem was the next step: confirmation. “Firstly, we need to understand the star,” Barclay said. “Astroseismology helps a lot here.” Astronomers have made strides in eliminating the false positives in this search, but there’s only so far they can go. “Not knowing which are the real planets is probably something we are going to have t get used to.” Some of the other talks at the session included possibly detecting interactions between an extrasolar world and its host star, and technical details on the upcoming FINESSE mission, which looks like it’ll pick up where the Kepler mission leaves off.
The session’s final talk, “The Effect of Planets Beyond the Ice Line on the Accretion of H20 by Habitable Zone Rocky Planets,” by Jack J. Lissauer, also of the NASA Ames Research Center, shifted the focus from observations into theory. He discussed models that took into account the likelihood of water dispersal on a rocky planet based on the presence of gas giants farther away from the host star. (Current theories suggest that Earth got its bounteous water supply from impacts of ice-laden comets and meteorites, perhaps originally sent on their way by planets like Jupiter.) His results were preliminary, and he was sure to emphasize that “chaos is also important,” but then suggested that “Jupiters are not absolutely necessary.”
Ann Fienup-Riordan of the Artic Studies Center discusses the Yup’ik peoples’ understanding of the world and how they cope with changing conditions. // photo by Bill Andrews
Finally, the last lecture I went to brought everything full circle, as it focused on the setting for this meeting, just like the first talk on Monday. “Yup’ik Understandings of the Environment: ‘The world is Changing Following Its People’” by Ann Fienup-Riordan of the Artic Studies Center here in Anchorage, Alaska, was all about the area’s original inhabitants and how they’ve adapted to the changing world, from increasing American-ization (at the expense of their Yup’ik identity) to climate change and the economy. Fienup-Riordan used astronomy to illustrate how the Yup’ik (she pronounced it “YOU-pick”) saw the world and interacted with it: Stars were not considered objects, but rather holes in the sky world through which spirits might look down; children are told not to respond to the sounds of the northern lights, lest they be taken away. After so much science all week, it was refreshing to end the conference with a reminder of the awesome, otherworldliness of the night sky. (Fienup-Riordan joked that when she told the elders she’d be giving a speech at an astronomy conference here in June, they smiled and wondered why the astronomers would come when there are no stars. I’ve wondered the same thing myself more than once.)
And that’s it! I hope you’ve enjoyed my coverage of AAS’s 220th meeting, and gotten your fix until the next one in January. It’s been a fun and eye-opening time for me here in Anchorage, but I have to confess it’ll be nice to return to a land that occasionally gets dark. (I’ve always been more of a night person.)