Launched in December of 2013, the European Space Agency (ESA)’s GAIA Mission will be the next great mission to find exoplanets, planets orbiting stars other than our own Sun.
However, GAIA’s main mission is not to search for planets, but to look at the motion, physical characteristics, and distance of up to one Billion stars with incredible precision. It’s a given that the satellite will invariably find planets by seeing the ‘wobble’ of a star due to the gravity of a planetary system.
One of the strengths that GAIA posesses over other exoplanet studies is that it will search a large area of sky instead of being limited to one particular region of space. During its five year mission, the satellite could find up to 21,000 exoplanets, and if extended for another five years, that number could rise to over 70,000.
The radial velocity method of finding exoplanets involves the use of the doppler effect and the fact that a planet doesn’t orbit a star, rather the planet and the star orbit a point in between them. Since stars are much more massive, that gravitational balance point is usually inside the star, causing a ‘wobble’ effect in the star. That wobble can be detected with the doppler effect here on Earth, and the size of the wobble can indicate the the mass of the planet relative to the star.
I’ve always been fond of exoplanet astronomy, there’s something delightfully science fiction about it all. Here’s hoping that in my lifetime we will find worlds that can host human life, or worlds that already host a different type of life altogether.