Day 9: MIT Lecture on the Kepler Mission

Cost: Free
Difficulty: 3 (due to vicarious embarrassment from weird question guy)
Time: 1 hour

Kepler is NASA's space-based telescope specially built to search for potential Earth-like planets in a region of the sky. Specifically, to look for planets that are within a factor of two of Earth's size and at a distance from their star where water might occur in liquid form.

MIT's Astrophysics department opened one of their lectures to public being given by Sara Seager.

Sara Seager, Exoplanet Researcher

Basically, Kepler looks at stars and attempts to determine whether they are likely to have planets orbiting them by measuring dips in the stars apparent brightness as the planet transits the star, that is, passes between  it and us. Since the planets (especially the planets we care about) are very small compared to the star, the change in brightness is very small. So a planet's existence can only be inferred from multiple orbits around the star.

Kepler has found over 1200 planet candidates (stars that exhibit a periodic brightness dip consistent with a planet), 15 confirmed planets, and approximately 65 Earth-like candidates.

The normal registered students for the course were outnumbered about 2:1 by the public. I love that MIT opens some of these lectures to the public (except for that one guy who sat at the back and asked really weird and inappropriate questions about UFOs and government conspiracies).