Planets said possible in Milky Way center

CAMBRIDGE, Mass., Sept. 12 (UPI) -- While the center of the Milky Way may be an inhospitable place for a planet to form, a recent discovery shows it's possible, U.S. astronomers say.

In the center of our galaxy stars crowd each other, supernova explosions blast out shock waves and intense radiation, and a super-massive black devours anything that comes near.

And yet, astronomers at the Harvard-Smithsonian Center for Astrophysics report, planets still can form in this cosmic maelstrom.

The proof is the discovery of a cloud of hydrogen and helium plunging toward the galactic center, a cloud they argue represents the shredded remains of a planet-forming disk orbiting an unseen star.

"This unfortunate star got tossed toward the central black hole. Now it's on the ride of its life, and while it will survive the encounter, its protoplanetary disk won't be so lucky," lead study author Ruth Murray-Clay said.

A likely source of the stray star is a ring of stars known to orbit the galactic center at a distance of about one-tenth of a light-year, astronomers said.

And although this particular star's protoplanetary disk is being destroyed, the stars that remain in the ring can hold onto their disks and may form planets despite their hostile surroundings, they said.

"It's fascinating to think about planets forming so close to a black hole," astronomer Av Loeb said. "If our civilization inhabited such a planet, we could have tested Einstein's theory of gravity much better, and we could have harvested clean energy from throwing our waste into the black hole."