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.
How to Search for Exoplanets
How are scientists searching for extrasolar planets? Read here of the different approaches, their strengths and weaknesses, and how planet hunters are pursuing them all.
Catalog of Exoplanets
We recommend the Paris Observatory's Extrasolar Planets Encyclopaedia. The Planetary Society no longer maintains our own Catalog of Exoplanets.
Our Exoplanets Research
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.
Our own Dr. Bruce Betts is once again teaching his Introduction to Planetary Science and Astronomy college course online. Come join him.
Posted by Bruce Betts on 2014/09/26 05:59 CDT
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.
Earth and its solar system compatriots all have nearly circular orbits, but many exoplanets orbit their stars on wildly eccentric paths. Is our home system strange? Or is our sense of the data skewed?
Posted by Bruce Betts on 2014/04/25 04:30 CDT
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.
Update from Debra Fischer and her team on the intriguing results of their observations of the main Alpha Centauri stars, as well as future plans.
Our Advocacy Program provides each Society member a voice in the process.
Funding is critical. The more we have, the more effective we can be, translating into more missions, more science, and more exploration.