- An asteroid known as ‘Oumuamua is the first of its kind ever spotted by astronomers.
- It was reclassified as an interstellar asteroid, a newly discovered category, after being mistaken for a comet.
- It is up to one-quarter mile wide and very elongated, which gives it a cigar-like shape.
An asteroid that sped through our solar system has drawn the attention of astronomers with its deep space origins and out of the norm characteristics.
It was first discovered on Oct. 19 by a team of researchers using the Pan-STARRS1 telescope at the University of Hawaii, according to an October release from the space agency. Its name, which is of Hawaiian origin, means “a messenger from afar arriving first.” The scientists realized it was different and from a solar system outside of ours due to its unusual motion.
“This is the most extreme orbit I have ever seen,” NASA Center for Near-Earth Object Studies (CNEOS) scientist Davide Farnocchia said in the October release. “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.”
In this most recent observation of ‘Oumuamua, the scientists discovered that it is up to one-quarter mile wide and very elongated. They believe it is likely 10 times as long as it is wide, rocky with a slightly reddish hue and has a cigar-like shape.
Researchers also believe the asteroid has been unattached to a star system and just floating through the Milky Way for hundreds of millions of years before finding its way into our system, states the release.
After initially being categorized as a comet, the celestial object was reclassified as an interstellar asteroid, according to a release from the International Astronomical Union (IAU). ‘Oumuamua was moved into the newly-discovered class of objects due to its “ hyperbolic orbit and record-breakingly high eccentricity” and the fact that it never appeared to be bound to our solar system by gravitational pull.
“For decades we’ve theorized that such interstellar objects are out there, and now – for the first time – we have direct evidence they exist,” NASA Science Mission Directorate associate administrator Thomas Zurbuchen said in the NASA release. “This history-making discovery is opening a new window to study formation of solar systems beyond our own.”
The asteroid’s characteristics suggest it is made up of rocks and possibly metals, it does not have any water or ice, and that its surface became reddened due to irradiation from cosmic rays over the course of hundreds of millions of years, states the release.
Along with her team of scientists, Institute for Astronomy astronomer Karen Meech found that the asteroid “varies in brightness by a factor of 10 as it spins on its axis every 7.3 hours,” according to the release. No other known comet or asteroid has had such a wide variety of brightness or such a vast ratio between its length and width.
“This unusually big variation in brightness means that the object is highly elongated: about 10 times as long as it is wide, with a complex, convoluted shape,” said Meech. “We also found that it had a reddish color, similar to objects in the outer solar system, and confirmed that it is completely inert, without the faintest hint of dust around it.”
Currently, ‘Oumuamua is roughly 124 million miles away from Earth and is traveling at a rate of about 85,700 miles per hour. It’s expected to pass Jupiter’s orbit in May 2018 and travel beyond Saturns orbit in January 2019.
Astronomers will be using large, ground-based telescopes to monitor ‘Oumuamua until it becomes too faint to pick up. It should no longer be detectable sometimes after mid-December, according to NASA.
“We are fortunate that our sky survey telescope was looking in the right place at the right time to capture this historic moment,” NASA Planetary Defense Officer Lindley Johnson said in the release. “This serendipitous discovery is bonus science enabled by NASA’s efforts to find, track and characterize near-Earth objects that could potentially pose a threat to our planet.”