Latest planet find fuels curiosity

SPACE

WASHINGTON — Astronomers have found yet another planet that seems to have just the right Goldilocks combination for life: not so hot and not so cold. It’s not so far away, either.

This big, dense planet is rocky, like Earth, and has the right temperatures for water, putting it in the habitable zone for life, according to a study published Wednesday in the journal Nature.

It’s the fifth such life-possible planet outside our solar system revealed in less than a year. In the constellation Cetus, the planet is 39 light years, or 230 trillion miles, away.

“It is astonishing to live in a time when discovery of potentially habitable worlds is not only commonplace but proliferating,” said MIT astronomer Sara Seager, who wasn’t part of the study.

The first planet outside our solar system was discovered in 1995, but thanks to new techniques and especially NASA’s planet-hunting Kepler telescope, the number of them has exploded in recent years. Astronomers have now identified 52 potentially habitable planets and more than 3,600 planets outside our solar system.

The latest discovery, called LHS 1140b, regularly passes in front of its star, allowing astronomers to measure its size and mass. That makes astronomers more confident that this one is rocky, compared with other recent discoveries.

In the next several years, new telescopes should be able to use the planet’s path to spy its atmosphere, said Harvard astronomer David Charbonneau, a co-author of the study. If scientists see both oxygen and some carbon in an atmosphere, that’s a promising sign that something could be living.

The planet belongs to a class of planets called superEarths that are more massive than Earth. Thirty-two of the potentially habitable planets found so far are considered super-Earth-sized.

The new planet was found using eight small telescopes in Chile and help from an amateur planet-hunter, Charbonneau said.