Meteor of Interstellar Origin May Have Slammed into Earth in 2014 | Astronomy



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A meteor seen on the South Pacific, off the northern coast of Papua New Guinea, in a new edition of Harvard University. If confirmed, the object will be only the second known visitor of the Solar System; the other is' Oumuamua, a fast moving comet of extrasolar origin discovered in October 2017.

A fireball. Image credit: NASA's Office of Safety and Mission Insurance / Sci-News.com.

A fireball. Image credit: NASA's Office of Safety and Mission Insurance / Sci-News.com.

"'Umuman was first interstellar object detected in the Solar System by Pan-STAARS," said Harvard University astronomers Amir Siraj and Abraham Loeb.

"Several follow-up studies of Oumuamua have been conducted to understand their origin and composition. Its size is estimated to be 656 feet (200 m), based on NASA's Spitzer Space Telescope constraints on its infrared emission given its temperature. "

"Since there should be a greater abundance of interstellar objects smaller than 'Oumuamua, we could observe small interstellar objects impacting the Earth's atmosphere."

The scientists analyzed 30 years of data from the CNEOS (Center for NEO Studies at NASA's Jet Propulsion Laboratory) catalog of bolide events.

They found that a meteor detected at 17:05 GMT on January 8, 2014 had an unusually high pre-impact speed.

"Accounting for the motion of the Earth relative to the Sun and the motion of the meteor relative to the Earth, we found that the meteor had a pre-impact heliocentric velocity of 60 km / s, which implies that the object was unbound (cam from outside the Solar System), "they said.

The astronomers determined that the meteor had a mass of 460 kg and was between 2.6 and 3.3 feet (0.8-1 m) in diameter.

They also concluded that it was important in the planetary system or in the thick film of the Milky Way Galaxy.

"We estimate the impact of similarly sized objects with the Earth to be at least 0.1 per year (once every 10 years)," Siraj and Professor Loeb said.

"Future meteor surveys could flag incoming objects with excessive heliocentric velocities for follow-up pre-impact observations."

"Spectroscopy of gaseous debris from these objects as they burn up in the Earth's atmosphere would reveal their composition. Some isotope ratios are expected to be markedly different for interstellar origin compared to the Solar System, could validate an interstellar origin. "

"Our discovery also implies that at least 450 million similarly sized interstellar bolide events have occurred over Earth's lifetime," they added.

"Potentially, interstellar meteors could deliver life from another planetary system and mediate panspermia."

The team's paper will be published in the Astrophysical Journal.

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Amir Siraj & Abraham Loeb. 2019. Discovery of a Meteor of Interstellar Origin. ApJ, in press; arXiv: 1904.07224

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