The first known asteroid from interstellar space has been observed and measured, and the object is exceptionally weird, reports Phys.org.
The unique rock was first spotted when the Pan-STARRS 1 telescope in Hawaii picked up a faint point of light moving across the night sky. Measurements of the object's trajectory quickly made it obvious that it couldn't possibly be from our solar system; this was an interstellar asteroid, a momentary visitor to our neighborhood that had likely been wandering around alone in space for hundreds of millions of years.
Not only is this asteroid the first known interstellar object discovered to pass through our solar system, but its shape and appearance seems to defy all expectations. It's dark reddish in color and appears highly elongated; cigar-shaped. In fact, its shape harkens back to the movie "Star Trek IV: The Voyage Home," where Capt. Kirk and crew head back to Earth only to discover that a nefarious cigar-shaped object has entered the solar system, broadcasting the sounds of humpback whales, and is threatening to destroy the planet.
Thankfully, this object isn't quite so talkative and hostile, and already looks to be rapidly departing the solar system. Scientists have named it "Oumuamua." ("Ou" means 'reach out for', and "mua", with the emphasis on the second "mua", means 'first, in advance of' — reflecting the nature of the object as a "scout" or "messenger" from the past.)
"We had to act quickly," explained team member Olivier Hainaut from European Southern Observatory in Garching, Germany, about discovering the object's rapid escape trajectory. "'Oumuamua had already passed its closest point to the Sun and was heading back into interstellar space."
Researchers surmise that 'Oumuamua's dark, red color is indicative of a high metal content that has been irradiated from cosmic rays over the course of millions of years. Since the object has probably been wandering the Milky Way unattached to any solar system for so long, its origin is extremely difficult-- perhaps impossible — to pinpoint. Scientists are racing to learn as much as they can about 'Oumuamua before it leaves us forever, but its brief visit might leave us with more questions than answers.
Although it's the first interstellar space rock ever observed, astronomers estimate that we likely have at least one such alien visitor per year. So after 'Oumuamua leaves us, we'll just have to keep looking for more.
"We are continuing to observe this unique object," said Hainaut, "and we hope to more accurately pin down where it came from and where it is going next on its tour of the galaxy. And now that we have found the first interstellar rock, we are getting ready for the next ones!"
Check out this breathtaking video, compiled by ESO, for more info about this wild object: