Astronomers revisit dwarf stars’ promise

An Earth-like planet — and with it, perhaps life — does not have to orbit a Sun-like star. That idea has inspired astronomers to widen their search for habitable exoplanets to systems surrounding M-dwarfs — stars that are much smaller, redder and cooler than the Sun. Although a project begun in 2008 found just one planet near such a star, data from NASA’s Kepler telescope suggest that astronomers should not give up on the approach, and several M-dwarf campaigns are now adjusting their searches.

“I want to know if life can exist on a planet like Earth in a different environment,” says astronomer Zachory Berta-Thompson at the Massachusetts Institute of Technology in Cambridge. “That would be one of the most fascinating astrophysical experiments.