Is ‘Oumuamua a probe sent by aliens? Probably not

When you think of an alien, you probably picture a little gray man in a skintight jumpsuit piloting a flying saucer, not an amorphous, cigar-shaped hunk of rock hurtling through our solar system.

Scientists studying the mysterious interstellar object ‘Oumuamua, didn’t make that connection either until Avi Loeb, chair of Harvard’s astronomy department, suggested it. Though not many took him seriously, given how much uncertainty surrounds this visitor from outer space, Loeb is not backing down.

‘Oumuamua, a Hawaiian name that roughly means "first distant messenger," is an asteroid first discovered on Oct. 19, 2017, and it’s been puzzling researchers ever since. Not only was its trajectory unlike anything previously encountered, but it displayed some strange behavior that made it difficult to classify. Observers first classified it as a comet, but it was quickly changed to an asteroid because there was no coma, the glowing “envelope” surrounding the body of the comet due to the sublimation of ice caused by the sun. Researchers later changed it back to a comet because the object displayed strange accelerations that couldn’t be explained by gravity alone, indicating that something must be coming out of the comet.

Loeb offers an alternative explanation that would neatly answer all the questions about ‘Oumuamua, if it weren't so implausible. According to Loeb's paper, the object is a piece of debris from a destroyed alien probe powered by a theoretical solar sail, a propulsion technology based on the idea of harnessing the radiation emitted by stars. Over time, a solar sail could generate enough velocity to exit a solar system.

‘Oumuamua could be a busted up alien probe gliding through space on a solar sail, or it could be an unexplainable low-activity comet. There’s no way of verifying either way, because ‘Oumuamua has long since left our solar system. In fact, because its proposed size and shape were off estimation, no one could even get a good photo.

Though our interstellar visitor is gone, the debate over its classification remains, and a year later, is still going strong. Loeb’s theory has taken the media by storm, the widespread coverage leading to the spread of rumors and sensationalist content.

Predictably, astronomers aren’t thrilled about this. As Benjamin Weiner of the University of Arizona expressed in a tweet this past Wednesday, Loeb’s speculation does a disservice to the scientific community, with scientists now working overtime to stop the spread of false information. In a time when science is often decried as fake news (think about all those global warming deniers), these frustrations are understandable.

Whatever you may think about ‘Oumuamua, its brief visit reminds us all that the universe is astoundingly large, and that we are but a single speck of dust in a cosmic ocean. Who knows? Maybe there are aliens out there, launching more probes as we speak.