Confirmed! A tiny nearby exoplanet with only 40% of Earth's mass

A planetary system just 35 light years from Earth hosts four and possibly five planets. This includes one (if it exists) that's squarely in its star's habitable zone, and another that's the lightest-weight planet ever found using the radial velocity method: It has only 40% of Earth's mass. That's pretty cool.

The host star is a red dwarf called L98-59, which is substantially smaller, cooler, and dimmer than the Sun, shining only 1% as bright as our own star. Three planets were already known to ...