An extrasolar planet, or exoplanet, is a planet outside the Solar System.   One of the ways to detect an exoplanet is to carefully observe the brightness of the star over time.  As the planet passes between the star and the earth the brightness of the star decreases slightly.

Exoplanet Detection

Exoplanet Transit Simulator

The Kepler Mission

The Kepler Spacecraft was launch in March 2009.  The Kepler Mission is specifically designed to survey a small portion of our region of the Milky Way galaxy to discover dozens of Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets. 

Kepler uses the exoplanet transit method of detecting extrasolar planets.

Current News

Student Project Kepler exoplanet hunt and identification.

As of October 27, 2011, 695 extrasolar planets (in 571 planetary systems and 81 multiple-planet systems) have been identified.  For more information on exoplanets, click here.

For more information on student or amateur exoplanet hunting download this book.

For a lesson plan, click here.

Simulator courtesy of University of Nebraska-Lincoln