'Alien' rock could be first confirmed object from outside our solar system

James Marshall
October 28, 2017

"We have long suspected that these objects should exist, because during the process of planet formation, a lot of material should be ejected from planetary systems", said IfA astronomer Karen Meech, who specializes in small objects such as comets and asteroids.

Currently, the staff of the worldwide astronomical center virtually nothing is known about the "outside" of comet C/U1 2017.

If the comet does come from another star like Vega, light reflecting off it could reveal its basic composition and possibly, by extension, that of a solar system too distant to explore within our lifetimes.

The U.S. space agency does think the object recently spotted on telescopes is likely from outside our solar system, which, if true, would make it the "first interstellar object to be observed and confirmed by astronomers". Weryk contacted IfA graduate Marco Micheli, who had the same realization using his own follow-up images taken at the European Space Agency's telescope on Tenerife in the Canary Islands.

The object appears to less than a half-kilometer in diameter, and it's moving at just over 40 kilometers per second - faster than our speediest probes, but still pretty slow for an interstellar visitor. Robert Weryk from the the University of Hawaii was the first to identify the object.

Astronomers rightfully got excited, since their observations could mark the first detection of a comet or asteroid from interstellar space, or the void between stars.

Weryk looked through the archives for the Pan-STARRS telescope, which conducts nightly sky surveys in search of celestial objects moving through the space near Earth, and found the mysterious body in images as far back as early September. They also tend to come from two zones: the Kuiper Belt beyond Neptune, or the Oort Cloud closer to the edge of the solar system.

"This is the most extreme orbit I have ever seen", Davide Farnocchia, a scientist at NASA's Center for Near-Earth Object Studies at the Jet Propulsion Laboratory, said in a news release. Tugged by the sun's gravity, it reversed course and hurtled back above the elliptic at an angle, passing about 15 million miles from Earth on October 14. "We can say with confidence that this object is on its way out of the solar system and not coming back".

For now, the object is being called A/2017 U1. Astronomers are now working to point telescopes towards the object to obtain more data.

The team then figured out its provenance by observing its orbit.

Because no interstellar asteroid has ever been seen before, the International Astronomical Union has no rules for naming the new object. Neither seems to be the case for A/2017 U1.

The Pan-STARRS1 Observatory on Halealakala, Maui, opens at sunset to begin a night of mapping the sky. JPL hosts the Center for Near-Earth Object Studies (CNEOS).

Whatever it is, NASA is fairly certain it's a unique object.

Other reports by Click Lancashire

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