The materials needed to create rocky planets are common in the universe, according to new information from the planetary graveyards around dead stars.
Astronomer Michael Jura of the University of California, Los Angeles, found a pattern in the debris around some of the brightest known white dwarfs—the remains of dead sunlike stars.
His study reveals chemical similarities suggesting that, when the white dwarfs were alive, they could have hosted terrestrial worlds akin to Earth, Venus, Mercury, or Mars.
Jura presented his findings during a Monday press briefing at the 213th meeting of the American Astronomical Society in Long Beach, California. The results will appear in a future issue of the Astronomical Journal.
Also during the briefing, a separate team of astronomers announced new data that suggest gas giant planets like Jupiter must form relatively quickly after the birth of a star, within two to five million years.
Skeleton Crew
A sunlike star in its death throes swells into a red giant, devouring its innermost planets and disturbing the orbits of outer planets and asteroids. The star then collapses to become a small but dense white dwarf.
Our sun has the potential to undergo this process in about five billion years.
(Related: "Solar System's Fate Predicted by Nearby White Dwarf?" [December 21, 2006].)
Sometimes the surviving asteroids get knocked off course, veer too close to a white dwarf, and are ripped apart by its intense gravity, leaving dust and debris.
Using infrared data from the Spitzer Space Telescope, UCLA's Jura found asteroid debris around at least one percent of the thousand brightest known white dwarfs.
Analyzing the chemical composition of this dust allowed Jura to see that eight white dwarf systems have several key traits in common with each other and with our solar system, suggesting they all once had similar planetary bodies.
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