Extrasolar Planets

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.

Latest Blogs

Apparent trajectory of Alpha Centauri B around Alpha Centauri A

Update on the search for planets in the Alpha Centauri system

Posted by Bruce Betts on 2014/04/04 10:29 CDT | 1 comments

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.

Bruce Betts screen shot teaching CSUDH Introductory Astronomy class with Saturn in background.

Take My Free Online College Introduction to Planetary Science and Astronomy CSUDH Class

Posted by Bruce Betts on 2014/02/05 05:02 CST | 7 comments

Our own Dr. Bruce Betts is once again teaching his Introduction to Planetary Science and Astronomy college course online. Come join him.

Beta Pictoris b from the Gemini Planet Imager

Planetary Radio: The Gemini Planet Imager

Posted by Mat Kaplan on 2014/01/14 11:06 CST | 1 comments

It's very nice to infer the existence of planets circling other stars. It's even better to see them. This new instrument has just become the most powerful exoplanet viewer yet created.

Alpha Centauri Planet Hunt Update

Posted by Bruce Betts on 2013/10/15 11:27 CDT | 2 comments

An update from Yale’s Debra Fischer about the Alpha Centauri planet hunt, partially sponsored by The Planetary Society, as well as her team’s efforts to remove “noise” from parent stars to help find exoplanets.

Europe Will Select Its Next Major Science Mission in November

Posted by Van Kane on 2013/09/25 01:22 CDT | 2 comments

The European Space Agency will announce two major science missions this November, one of which is likely to be devoted to solar system exploration.

Destiny or Chance Revisited, by Stuart Ross Taylor

Book review: Destiny or Chance Revisited

Posted by Emily Lakdawalla on 2013/09/04 01:02 CDT | 1 comments

What have the recent discoveries of thousands of exoplanets told us about how we got here, and whether we are alone? In Destiny or Chance Revisited, Stuart Ross Taylor attempts to answer those two questions.

Upgraded Alpha Centauri Planet Search Underway

Posted by Bruce Betts on 2013/07/26 04:32 CDT

The Planetary Society sponsored Alpha Centauri planet search started using a newly upgraded system in May. Here is a quick update including info from project leader Debra Fischer from Yale about their new system.

Planetary Society Weekly Hangout, Thu Feb 14 1200PT/2000UT: Courtney Dressing

Posted by Emily Lakdawalla on 2013/02/14 01:40 CST | 3 comments

Emily Lakdawalla and Courtney Dressing talked about just how common Earth-sized exoplanets may be in our neighborhood. Watch the replay here.

The raw data behind an Earth-like exoplanet

Posted by Jason Davis on 2013/01/11 03:29 CST | 14 comments

Taking a closer look at KOI 172.02, a super-Earth exoplanet sitting in its solar system's habitable zone.

Planetary Society Hangout: Jan 10th, 2013 - AAS Coverage with Astronomer Meg Schwamb

Posted by Casey Dreier on 2013/01/10 01:00 CST | 1 comments

Join Casey Dreier and Emily Lakdawalla as they are joined by Dr. Meg Schwamb from Yale University. They will discuss the latest announcements from the American Astronomical Society 2013 conference and Dr. Schwamb's research in outer solar system bodies.