Scientists dazzled by solar system's first-known interstellar visitor

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In a study published in the journal Nature on November 20, Meech's team writes that the detection of 'Oumuamua suggests "previous estimates of the density of interstellar objects were pessimistically low", and that upcoming upgrades to asteroid survey telescopes (like Pan-STARRS) will likely detect more of these interstellar visitors over the coming years.

First thought to be merely another comet or asteroid, astronomers were excited to learn, based on the odd orbit of the object, this asteroid had originated from another solar system entirely, making it the first observed interstellar asteroid. We know that our own Solar System is constantly ejecting small asteroids.

The interstellar visitor has an approved name: Oumuamua (OH'-moo-ah-moo-ah), which in Hawaiian means a messenger from afar arriving first. Its appearance suggests 'Oumuamua is dense, made up of rock or metallic elements and lacks significant water or ice, scientists said. "This change in brightness hints that 'Oumuamua could be more than 10 times longer than it is wide - something which has never been seen in our own solar system".

This very deep combined image shows the interstellar asteroid 'Oumuamua at the centre of the picture. Observations from ESO’s Very Large Telescope in Chile and other observatories around the world show that this unique object was travelling through space for millions of years before its chance encounter with our star system.

The other group of astronomers, led by David Jewitt, University of California Los Angeles, estimated how many other interstellar visitors like it might be in our solar system. Traveling at 27 miles per second (44 kilometers per second), the comet is headed away from the Earth and Sun on its way out of the solar system. Paul Chodas, manager of the Center for Near-Earth Object Studies at NASA's Jet Propulsion Laboratory, said in a statement.

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Its location is approximately 200 million kilometres from Earth - the distance between Mars and Jupiter - though its outbound path is about 20 degrees above the plane of planets that orbit the Sun. 'Oumuamua's trajectory will next take it toward the constellation Pegasus. "It is going extremely fast, and on such a trajectory that we can say with confidence that this object is on its way out of the solar system and not coming back".

'Oumuamua made its closest approach to Earth on October 14 - before its discovery - at a distance of about 15 million miles (24 million kilometers), or around 60 times the distance between the Earth and the moon.

'Oumuamua (pronounced oh MOO-uh MOO-uh) may be on its way out of our solar system, at a speed of 138,000 km per hour, but telescopes on the ground continue to watch it, and both the Hubble and Spitzer space telescopes are tracking it this week.

It was clear that this asteroid came from outside of our Solar System because of the path it follows...
The International Astronomical Union, the organization responsible for formally naming celestial objects, had to create a new classification for interstellar objects earlier this month, resulting in in the "I" in the official name 1I/2017 U1. Unfortunately, it is already too faint for such in-depth follow-up work, and will only get fainter as it moves further away.