Diversity and Exoplanets...

NASA: Kepler Discovers Three Small Exoplanets

Astronomers using data from NASA's Kepler mission have discovered the three smallest planets yet detected orbiting a star beyond our sun. The planets orbit a single star, called KOI-961, and are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars.

All three planets are thought to be rocky like Earth, but orbit close to their star. That makes them too hot to be in the habitable zone, which is the region where liquid water could exist. Of the more than 700 planets confirmed to orbit other stars -- called exoplanets -- only a handful are known to be rocky.

"This is the tiniest solar system found so far," said John Johnson, the principal investigator of the research from NASA's Exoplanet Science Institute at the California Institute of Technology in Pasadena. "It's actually more similar to Jupiter and its moons in scale than any other planetary system. The discovery is further proof of the diversity of planetary systems in our galaxy."

The team was lead by John Johnson, a member of the National Society of Black Physicists, also on the team - Vanderbilt University's Keivan Stassun, who describes himself thus: "I get my strange genetic admixture from my Mexican mother and Iranian father. My first name is Persian for Saturn, my middle name was my (maternal) grandmother's, and my last name is my German stepfather's."

NASA: NASA's Kepler Mission Finds Three Smallest Exoplanets