At just 217 light years, Nasa’s Kepler Mission has discovered three more planets of interest: Kepler-37b, Kepler-37c and Kepler-37d. Kepler-37b is the smallest extra-solar planet yet detected (smaller than Mercury and a little bigger than our Moon). Kepler37-d is a very large “habitable zone” planet–about twice the size of Earth; its gravity promises to be a stiff challenge for any visitors. The middle planet, Kepler37-c is much larger than Mars, just a little smaller than Venus and about three-fourths the size of Earth, making it an exciting find considering its location in the habitable zone of its solar system where liquid water is possible.

The scientific objective of the Kepler Mission, according to NASA, is to “explore the structure and diversity of planetary systems” by surveying a large sample of stars to, among other things:

• Determine the percentage of terrestrial and larger planets that are in or near the habitable zone
• Determine the sizes and shapes of the orbits of these planets
• Estimate how many planets there are in multi-star systems
• Determine the properties of those stars that harbor planetary systems.

The Mission relies on a space-based light-detecting telescope that continuously searches a specific part of the sky for evidence of planetary transits across the face of distant stars.

The region of space surveyed, in the Cygnus and Lyra constellations, contains about 100,000 stars similar to our sun in the Milky Way galaxy.

You can help. Since 2010, the Citizen Science Alliance has made Kepler data available through a web site, http://www.planethunters.org/,  allowing people to participate in the process of identifying transit events that might evidence planetary orbits. The project has been successful. The NASA algorithms used to analyze the light signatures under observation are very sophisticated, but even so, a thinking human can often spot patterns and items of interest that an algorithm can miss–a potential that has already been realized multiple times.

The Mission has been highly successful, and is scheduled to continue at least through 2016. The growing list of planets confirmed can be reviewed at NASA’s site about the Kepler Mission at http://kepler.nasa.gov/Mission/discoveries/. We can be confident the Mission algorithms will find many more. But the more people that participate the better the chances of finding even more.