New Study Reveals More About Mysterious 'Oumuamua Interstellar Asteroid
Since it was first spotted around a year ago, our solar system's first interstellar asteroid has been one of the most talked about objects in the galaxy. There's still some debate as to whether or not the "asteroid" is really an alien ship lying in wait (hence the name 'Oumuamua, which translates to "first messenger"). According to NASA, scientists do know a little more about the weird rock than they did a few months ago, but the new info doesn't do much to make it less mysterious.
According to a study recently published The Astronomical Journal, researchers using data from NASA's Spitzer Space Telescope were not able to detect 'Oumuamua a couple months after it was discovered. Noe being able to "see" it actually helped reveal some information about the asteroid, namely its size. The scientists were able to place a cap on just how big the cigar-shaped rock could be. They also determined that the asteroid's non-gravitational acceleration is caused by gases that are being expelled through air vents in its surface. "'Oumuamua has been full of surprises from day one, so we were eager to see what Spitzer might show," said study lead author David Trilling. "The fact that 'Oumuamua was too small for Spitzer to detect is actually a very valuable result."
Another interesting conclusion made the researchers is that Oumuamua is 10 times more reflective than the icy space rocks that are native to our solar system. When comets pass the Sun, some of the ice on their surface warms and turns to gas, which Phys.org says "refreshes" the comet and removes dust and debris to reveal more reflective ice. Oumuamua is not from our solar system, so it has been moving through space for millions of years without frequent trips past the Sun. The researchers believe that its one recent solar pass, combined with the gases that are being released by the asteroid is what contributed to its reflectiveness. The thing is, they can't really go back and confirm that or anything they think they know. "Usually, if we get a measurement from a comet that's kind of weird, we go back and measure it again until we understand what we're seeing," said co-author Davide Farnocchia of the Center for Near Earth Object Studies (CNEOS). "But this one is gone forever; we probably know as much about it as we're ever going to know."