fomalhautLast night I had the good fortune to fill my nerdy brain with information about exoplanets, courtesy of Alex Filippenko. Here, in a dumbed-down a probably slightly inaccurate form, is what I learned.

Dr. Fillippenko’s a pretty happy guy, and in his brief pre-history of the current state of exoplanets research, he brought up another smiley guy my favorite Greek philosopher, Democritus. I only learned about Democritus recently while reading You Are Here. He thought of the idea of atomic structure, but what I learned last evening is that back in around 400 BCE, he also proposed the existence of other solar systems. According to Wikipedia, “Plato is said to have disliked him so much that he wished all his books burned.” Hmm, Plato… jealous? As I said in my previous post, it’s hard to understand why we study Plato, who obviously had his head up his ass when compared with scientific theories of his peer. In addition, Democritus, like Filippenko, is always pictured smiling whereas Plato always looks fairly grim.

As of this writing, there’s been about 15 years of research. Before that, there was virtually no evidence of any planets outside our solar system. In that short time, about about 500 exoplanets have been discovered. That in itself is pretty amazing. You can see them all for documented for your self in the The Extrasolar Planets Encyclopaedia. At first all they found was huge, huge planets orbiting very close to the stars. They didn’t even believe they were planets at first because it seemed so weird — several times the size of Jupiter? 4 days orbits? But eventually they realized, no, these really exist. These type of planets were called Hot Jupiters. There’s easy to find because they’re huge and they move quickly, which means you don’t have to monitor for long before you can identify the orbit.

Filippenko discussed five methods for identifying planets, which I will briefly and poorly summarize below. Each method that was subsequently developed helped to find smaller and smaller planets. These detection methods are more accurately explained in Wikipedia.

As more methods have been created, exoplanets discovery has gone from planets about 100 times the size off earth to about 5 times. There have been about 3 super-earths discovered, meaning a planet 10 times the size of earth or less.

Now, all this planet discovery has led to another discovery which is that most solar systems identified are not at all like ours. There are hot jupiters, and also planets with elliptical (so-called eccentric) orbits. There are tidal planets, meaning they face only one way (like the moon), and do not rotate. Granted, life may flourish anywhere, but from what we know thus far (not much, really) it’s most likely to evolve when conditions are similar to earth. Thus the quest for a earth-like planet.

kepler_fov_hires.jpgTo this end, there is currently the Kepler Mission, which is a space observatory staring very diligently at a quadrant of space, a quadrant that for various reasons was chosen as the best area to observe for possible earths. Hmm… strange… isn’t that Vega in the diagram? That reminds me of a movie…

“Seti, man, that’s fringe… that must really chap his ass.”

I wonder if Sagan new about the potential for the Kepler Mission when he wrote Contact?


One Response to “Exoplanets”

  1. K on September 28th, 2010 6:09 am

    This nerge is way too fringe and out there and really chaps my ass!

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