Keep Track of Exoplanets with Planetary Society's New On-line Catalog

For Immediate Release
March 05, 2009

Mat Kaplan
Email: [email protected]
Phone: +1-626-793-5100

Ever since we discovered that the stars in the night sky were other suns, humankind has wondered if those suns were orbited by other worlds. That first extrasolar planet, or exoplanet, was discovered in the mid 1990s, and now, The Planetary Society presents an on-line Catalog of Exoplanets to keep track of the growing number of confirmed extrasolar worlds.

“With the launch of Kepler – NASA’s exoplanet-finding spacecraft – scheduled tomorrow, and ESA’s Corot already in orbit, our Catalog of Exoplanets will be particularly useful for keeping up with the many new upcoming discoveries from space and from the ground,” said Planetary Society Director of Projects Bruce Betts.

Researchers have discovered more than 300 exoplanets to date. Most are gas giants hundreds of times the mass of the Earth, many orbiting very close to their home stars. But as the sensitivity of the search and the range of detection methods have increased, so has the variety of known exoplanets. Planetary systems composed of as many as five planets have been discovered, some of them sharing similarities with our own solar system. Planet-hunters are also detecting smaller and smaller planets, as small as twice the diameter of the Earth. As detection techniques improve, scientists are closing in on the exoplanet we are all waiting for: an alien “Earth” orbiting a distant star.

The Planetary Society's Catalog of Exoplanets features an up-to-date list of all known exoplanets, along with essential information about each:

  • planet's location and home star
  • mass
  • orbital period
  • method by which it was detected, and
  • date of discovery.

There is also a wealth of additional information about each planet and parent star.

An animated graphic for each exoplanet shows its precise orbit and that of any other known planets in the system. Color coding identifies star types and sizes of planets.

“We live in an exciting era of discovery with exoplanets,” said exoplanet hunter Geoffrey W. Marcy, Professor of Astronomy at the University of California, Berkeley, “with new worlds found every month, sometimes every week. The Planetary Society’s on-line Catalog of Exoplanets is the perfect resource for the public to keep pace with new discoveries.”

The catalog also includes articles about exoplanet detection methods, which discuss the advantages and shortcomings of each. A special page is dedicated to "notable exoplanets," those that stand out from the crowd and tell us something unique about distant worlds. Whenever a new planet is detected, it will be added to the Exoplanet Catalog.

Funding to produce and maintain the Catalog of Exoplanets was provided by donations from members of The Planetary Society.

About The Planetary Society

With a global community of more than 2 million space enthusiasts, The Planetary Society is the world’s largest and most influential space advocacy organization. Founded in 1980 by Carl Sagan, Bruce Murray, and Louis Friedman and today led by CEO Bill Nye, we empower the public to take a meaningful role in advancing space exploration through advocacy, education outreach, scientific innovation, and global collaboration. Together with our members and supporters, we’re on a mission to explore worlds, find life off Earth, and protect our planet from dangerous asteroids. To learn more, visit