Exoplanets!

Exo! Exo! Read all about it!

Things are moving quickly now, very quickly. As of January 23, 2014, 1074 exoplanets in 812 planetary systems have been confirmed. That means that when this blog entry goes live, later this week, the information here will likely be out of date. That's how quickly new exoplanets are being discovered. More than one every two days in 2013.

But forget about that. Discovering exoplanets has become old news. It's only a matter of a decade or two till we've likely confirmed a hundred thousand of them (Thanks, Kepler!)*. Exoplanets ranging in size from many Jupiters to small Earths in every kind of orbit you can imagine, in single star, binary,trinary star systems.

And now for something completely different

The future is in exoplanet spectroscopy. Using spectroscopy to analyze an exoplanet's atmosphere. Here's how it works. Some of these exoplanets are positioned so that sometimes they appear between their star and Earth. At those times, the light from their star passes through the exoplanet's atmosphere and continues on to us. By analyzing the light that passes through the exoplanet atmosphere, and comparing that to the light from the star, we can determine, through spectroscopy, what is in that exoplanet's atmosphere. This technique has already been used to find water on a number of exoplanets.

NASA and the ESA (European Space Agency) already have proposed missions for the spectroscopy of exoplanets. In NASA's case, it's FINESSE (Fast Infrared Exoplanet Spectroscopy Survey Explorer). The ESA is planning the Explanet Characterization Observatory (EChO).

Dr. Seager from MIT has an excellent breakdown of the possibilities of exoplanet spectroscopy, including identifying the spectroscopic signatures of life on exoplanets.

The future's so bright...

Since the invention of the telescope around 1600, astronomers have worked hard to see as deep into space as possible. Observatories, Adaptive Optics, Space Telescopes, etc. have helped us discover distant wonders and revolutionized the way we think about the universe. But there has always been something very esoteric about astronomy. The distances and timescales are so large that they lose their meaning in everyday life. Tell someone there are 100 billion stars in our galaxy and the profundity of that statement rolls off of them. You might as well have said "gazillion" or "a lot". The number is just too large to have significant meaning.

But that second act of astronomy is ending.** Now the curtain rises on the third act. An act where we peer at our closest neighbors and look for the familiar. Astronomy that may tell us, in the not too distant future, "hey, we're pretty sure there is life on that earth-like exoplanet 25 light years away". Discoveries that aren't about oberving billion year old galaxy light, unimaginable distances away, but star systems filled with planets and life in our galactic backyard. Definitely an exciting time to be an astronomer. Discoveries await!

*This is a very conservative estimate.

** I'm suggesting the first act of astronomy was the observations by eye for thousands of years that preceded the telescope