Is our world unique? Is it the only one in existence, or are there others – perhaps many others – out there? Do other beings – maybe even intelligent ones – call these worlds their home, and live out their lives completely unbeknownst to us?
It was only in 1995 that we first discovered evidence that other stars had planets, as ours does. Now we have detected many thousands of other worlds, and evidence suggests that a majority of sun-like stars possess them. Most of these stellar systems bear little resemblance to ours. The easiest planets to detect are massive worlds located close to their stars, so "hot Jupiters" dominate the current list of exoplanets. As our surveys continue, however, we are discovering more and more Neptunes and even super-Earths, in orbits farther and farther from their suns.
Until just a few years ago, a plot of mass versus size of other worlds would have looked pretty sparse and uninformative. But thanks to the tireless efforts of exoplanet astronomers, we now know fairly precise masses and radii for hundreds of distant worlds.
The Planetary Society is launching a new collaboration with Yale exoplanet hunter Debra Fischer and her team, the Exoplanets Laser project. We will support the purchase of an advanced, ultra stable laser to be used in a complex system they are designing to push radial velocity exoplanet hunting to a whole whole new level.
Learn about the formation and origin of the Solar System and go beyond our neighborhood to investigate exoplanets (planets around other stars) in this video of class 11 of Bruce Betts' Introduction to Planetary Science and Astronomy class.