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Astronomers have detected an interstellar traveler previously unknown, an object that comes from outside the Solar System. Oumuamua’s discovery marks the first identification of an interstellar object and may mean that such objects are also found in other parts of our Solar System.
The space rock, also known as 1I / 2017 U1, was first observed on October 19 by Robert Weryk, who used the Pan-STARRS1 telescope that hunts space objects near the Earth that can pose a threat to our planet.
Looking back to the archive, the astronomers realized they have seen the object before. “Oumuamua appeared to be new in the neighborhood. It has an eccentric trajectory, one that does not seem to be a closed orbit. It is also above the solar system’s plan and does not seem to have passed near any known planet.”, said Karen Meech, a researcher at the Hawaii University Institute of Astronomy.
“We have found nothing in the Solar system that has this form. The shape of the orbit shows that it is not gravitationally connected to our Solar System. The sun has certainly influenced its trajectory because it has got close enough to it.”, she added.
Oumuamua seems to be long and thin, like a cigarette, with a length of about 400 meters and a width of only 40 meters. Astronomers have noticed that it rotates around its axis, looking brighter when it is showing full length to Earth. The object completes such a rotation in 7.3 hours.”
Oumuamua does not leave gaseous material like a comet, so the best hypothesis is that the object is an interstellar asteroid.
Asteroids are the “bricks” of the Solar System that have not become planets – which means their composition has not changed for billions of years. That’s why scientists consider them “space fossils”, objects that can indicate details of the formation and early days of the Solar System.
What about the space fossils that come from the outside of the system? They can provide invaluable insights into the history and formation of other solar systems. “It’s our first opportunity to look at a piece of material from another solar system.”, Meech said.
If anyone asks, the name Oumuamua is a Hawaiian word meaning messenger. Unfortunately, this interstellar visitor is already leaving, moving away at a speed of nearly 140,000 kilometers per hour. He passed on Mars on November 1, will pass by Jupiter in May next year and will visit Saturn in January 2019.