Dead star shows signs of earth-like planets

They figured out the chemical composition of a large asteroid that was ripped apart by gravitational forces as it approached GD 362, finding it was similar to the Earth’s crust. It was rich in iron and calcium and low in carbon, much like a strong rock, they said.

The white dwarf is surrounded by dusty rings, probably made up of objects shredded as they ventured too close.

“It’s probably quite similar to Saturn’s rings,” UCLA astronomer Michael Jura said in a telephone interview.

GD 362 once was a star similar to the sun. After billions of years, it ballooned into a “red giant” as part of its death process, expelling most of its outer material, then degenerated into a burnt-out remnant called a white dwarf.

The fact that the asteroid is so similar in make-up to the Earth, as well as the moon, indicates that rocky planets like our own may have orbited the star eons ago, Jura said.

And if such planets currently populate our solar system and existed in a planetary system around this white dwarf, they may well be fairly common in the universe, Jura added.

The research, based on observations made using the Keck I Telescope in Hawaii, will appear in the Astrophysical Journal.

It is the latest evidence found by astronomers indicating that planets like Earth are found outside our solar system. European astronomers in April said they detected the most Earth-like planet yet outside the solar system orbiting a star 20.5 light-years from here, with temperatures that could harbor water and perhaps life.

Jura said that his study’s fresh evidence of Earth-like planets outside our solar system lends support to the possibility of extraterrestrial life.