A Tiny Planet (Artist’s Concept)

NASA's Kepler mission has discovered a new planetary system that is home to the smallest planet yet found around a star like our sun, approximately 210 light-years away in the constellation Lyra.

The artist's concept depicts the new planet dubbed Kepler-37b. The planet is slightly larger than our moon, measuring about one-third the size of Earth. Kepler-37b orbits its host star every 13 days at less than one-third the distance Mercury is to the sun. The estimated surface temperature of this smoldering planet, at more than 800 degrees Fahrenheit (700 degrees Kelvin), would melt the zinc in a penny.

Astronomers don't think the tiny planet has an atmosphere or could support life as we know it, but the moon-size world is almost certainly rocky in composition.

NASA's Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. JPL managed the Kepler mission's development.