The bizarre interstellar visitor that whizzed through our Solar System late last year stunned scientists the world over. The object, named Oumuamua snuck up out of nowhere, cruising around the Sun and then slingshotting back out into space before most astronomers even knew what to make of it. Its strange shape and odd coloring were so strange that some researchers thought it might have been an alien probe checking us out.
Once that was put to rest, one of the more humorous twists to the story was the repeated flip-flopping of scientists who couldn’t decide whether it was a comet or an asteroid. It was initially thought to be a comet, but its lack of an iconic tail suggested otherwise. So, it was an asteroid, at least for a little while, but subsequent rounds of research suggested it was a comet again… then an asteroid, again. Now, yet another study has been published in Nature and, well, it’s definitely a comet. Again.
The new paper, which was led by an astronomer with the European Space Agency (ESA), takes a close look at the strange visitor as it speeds away from our Solar System. The data reveals that the object is speeding up as it exits our neighborhood, which shouldn’t be possible if it were just a rocky asteroid being flung by gravity.
Instead, the researchers say, the object being a comet would explain its acceleration. The idea being that gasses heated during Oumuamua’s close brush with our Sun are actually pushing it faster and faster, matching what we know about comets.
So, the cigar-shaped object is actually a comet after all… or so the scientists say.
It’s hard to overstate just how bizarre Oumuamua really is. It’s confounded so many researchers in so many ways that it’s not hard to see why some have pushed the theory that it might actually be a spacecraft of some sort. In fact, the entire situation was so odd that the Breakthrough Listen project aimed its electronic ears at the object in an attempt to hear if it was sending out signals, perhaps being controlled remotely from some unseen intelligence. That experiment turned up nothing but silence.
For now I guess we’ll just have to accept the very little we know about Oumuamua. That is, unless it decides to turn around and come back, and at this point that might not be entirely out of the question.