Oct 1, 2019

New study predicts more interstellar objects to fly through solar system

Miriam Kramer, author of Space
Gif: NASA/JPL-Caltech

A comet discovered at the end of August is just the second interstellar object spotted on a path through our solar system, but scientists think it may be a harbinger of more to come.

What's happening: According to a new study accepted for publication by The Astrophysical Journal Letters, astronomers should expect that at least a few, large interstellar objects will fly through our solar system each year.

Why it matters: These objects, which include this year's 2I/Borisov — formerly called C/2019 Q4 (Borisov) — and 2017's 'Oumuamua, represent the best chance scientists have to study material from distant solar systems at close range.

  • By learning more about comets and asteroids from elsewhere in the galaxy, researchers might be able to figure out just how unique our solar system is.

Details: The new study suggests that interstellar objects may be flung out of their solar systems during the planet formation process.

  • The authors of the study found that planets that form far from their star may eject a fair amount of material from their home solar systems, sending them out through interstellar space.
  • “This idea nicely explains the high density of these objects drifting in interstellar space, and it shows that we should be finding up to hundreds of these objects with upcoming surveys coming online next year,” Gregory Laughlin, an author of the study, said in a statement.
  • It's also possible there could be hundreds of smaller interstellar objects that pass through the solar system each year, according to the study.

Yes, but: This study is based on limited data, outside experts told Axios, and it will take new tools coming online in the coming years to truly characterize how many of these interstellar objects pass through the solar system annually.

  • "With LSST [Large Synoptic Survey Telescope] up and running in a few years (hopefully) we will be able to test whether this theory is right, and I look forward to that," Ye Quanzhi, an astronomer at the University of Maryland, told Axios via email.

Go deeper: NASA emails reveal agency's surprise at asteroid's near-miss of Earth

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