Re: Other Planets with Atmospheres
The short course:
1. Spectography is the best tool for determining the elements present in the atmosphere of planets.
2. Spectrographs split the wavelengths of gasses into separate colors - red to indigo- with bands running through them. Each gas has a uniqe signature "rainbow".
3. Because planets don't emit light, but rather reflect it, spectrography has traditionally only been effective in examining stars of various distances and only near planets. Like seeing writing through an envelope held up to a lamp, studying a planet as it transits across the face of its star can tell us what is "inside" that atmopshere.
4. There have been thousands of exoplanets found in the last few years. A very small minority of those have atmospheres that are dense enough, high enough (to prevent UV destruction), and gasses that could suggest the presence of life (as we know it).
5. It is likely that this technique will be a central technology in finding the first life beyond the solar system. With thousands of exoplanets found in the last few years, spectrography technology improving, race is on to find possible candidates for further study.
6. My grad student's work is to refine strategies to find other atmospheric components like temperature, the ratio of gasses, and anomalies, to help further identification of candidates.
7. I would answer questions, but OGF seems to think I have fallen off the flat Earth. Someone lower me a rope.