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Bam! Scientists Watch Distant Exoplanet Collision

An artist's depiction of a collision between two exoplanets.
An artist's depiction of a collision between two exoplanets.
(Image: © NASA/SOFIA/Lynette Cook)

Astronomers love a hot mess — at least when it can tell them more about how solar systems work.

When scientists studied a star system called BD +20 307 a decade ago, they saw a lot of warm dust. And when they checked in on the neighborhood again using SOFIA, an airplane-based telescope run by NASA and its German counterpart, scientists saw even more warm dust. That could be a sign that astronomers are seeing the residue of a fairly recent dustup.

"This is a rare opportunity to study catastrophic collisions occurring late in a planetary system's history," Alycia Weinberger, a staff scientist at the Carnegie Institution for Science in Washington, D.C., and the lead investigator on the project, said in a NASA statement. "The SOFIA observations show changes in the dusty disk on a timescale of only a few years."

Related: The Most Fascinating Exoplanets of 2018

Scientists know that giant impacts play an important role in shaping planetary systems. Close to home, astronomers believe that the moon formed during just such an impact. But that collision took place a long, long time ago, and scientists have to piece together the story of what happened from scattered clues.

That's just as well. It's better to watch such dynamics unfold in real time from afar because it would be awfully disruptive to try studying such an event nearby. Although dust isn't necessarily caused by collisions, warm dust should disperse and cool as a solar system ages. This distant solar system, about 300 light-years away, is located in a region full of stars at least a billion years old, which means birth debris should have cooled by now, according to the NASA statement.

And there aren't many events that should cause warm dust over as short a time frame (cosmically) as the scientists' observations of this star. That's why it's likely a planetary collision that's causing the mess, the research team said.

The research is described in a paper published April 12 in The Astrophysical Journal; you can also read a copy posted to the preprint server arXiv.org.

Editor's note: This story has been updated to clarify the age of the star the solar system surrounds. Email Meghan Bartels at mbartels@space.com or follow her @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook. 

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