Exoplanets

Last night at the monthly meeting of the South Bay Astronomical Society, we were treated to an excellent lecture given by Michelle Thaller of JPL. Thaller is a dynamic young woman with not only the scientific knowledge to accurately discuss her subject (the Spitzer Space Telescope) but also the gift of gab. It was amazing to watch her in action. Questions that were off topic were answered quickly and to the point, but then without even a breath she was back on topic. The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory and we have heard speakers from JPL before who gushed over the possibilities of Spitzer but never with this level of expertise in public speaking. You can hear a couple of her podcasts at the Spitzer website, one on M82 a starburst galaxy, "Seeing Smoke from a Galactic Fire," and one on comets, "Cotton Candy Comets."

Spitzer views the universe in the infrared wavelength and last night Michelle brought along an infrared camera to demonstrate what viewing things in this wave-length looks like. I think everyone was captivated by what they saw from the several youngsters in the audience (ages 7 and up), to the college students, to the guys who have been working in the space industry all their lives. (The El Camino College planetarium was packed.) We watched how holding an ice cube can turn your hand black, or how you can write with it by smearing it on your shirt. The camera can even see through things like a black plastic bag to see your warm hands inside. There is a video of Michelle on the Spitzer website briefly demonstrating the camera. Scroll down to First Person: Michelle Thaller. (You'll need Real Player for this one.) The video also shows an artist's conception of the Telescope, again very briefly.

The main topic of her talk, however, was about using infrared and Spitzer to find other planets both inside and outside our solar system (exoplanets). Infrared is good for this because planets do not emit light of their own but they do emit heat that can be detected by the telescope. Sometimes what the scientists do is to take an infrared reading of a star over a period of time and watch for changes. If the readings go down periodically, they can assume that a planet is orbiting the star and has been eclipsed by it when the readings are down. Michelle claims that close to 300 "planets" have been discovered not to mention all kinds of other objects which we may or may not call planets. Michelle was actually one of the scientists who got to vote on whether or not Pluto should be cast out of that special category, and she admitted she voted aye.

There are other things that Spitzer can do, like seeing through gaseous clouds to observe stars and galaxies hidden by the gas and dust. We saw some spectacular photos of Orion and the Eagle Nebula taken by Spitzer. And there are other things that Michelle could have talked about from black holes to string theory. Her enthusiasm and energy seemed boundless. I wonder who does her writing for her.