Oumuamua

Around 1837, something very strange entered our solar system. About 1400 feet long and 450 wide, this dark red object careened through our vicinity for nearly two hundred years until it finally came close enough to the sun to be observed. This viewing happened in October of last year, and by May, it had slipped past Jupiter’s orbit and out of sight again. By 2025, it will have crossed the boundary of the Kuiper belt, one of the outer edges of our solar system.

Dubbed “Oumuamua” by scientists, meaning “leader” or “scout” in Hawaiian, this is the first documented interstellar visitor to be seen traversing our corner of the universe. This already extraordinary object has a long list of additional anomalies: its odd shape, low thermal emission and high reflectivity being just a few. Possibly the most noteworthy, though, is its path of motion-- more specifically, its acceleration.

Simply put, rocks cannot speed up by themselves. They need to be acted upon by some outer force, usually gravitational, to change their velocity. However, the path of this object didn’t match how it should have been moving, considering the gravity that was acting upon it. The most simple explanation for this was that Oumuamua was “outgassing”, or expelling gas and dust, a process very common to comets. This theory seemed to fit fine; the force of the outgassing and the subsequent speed of the object all seemed in line to an average comet.

However, one critical detail kept this theory from being entirely credible: the lack of evidence of any kind of dust or gas being expelled. As far as scientists could tell by using methods previously successful in monitoring other comets, nothing was being emitted from Oumuamua as it tumbled around the sun. Although it’s important to keep in mind that interstellar materials may act differently from the rocks us earthlings are used to, an explanation for this odd behavior remains undiscovered.

So what is this mysterious traveler? Researchers at the Harvard Smithsonian Center for Astrophysics have published a paper speculating that “Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization”. The paper bases its argument on accounting for many of the object’s peculiarities. Another theory the authors pose is the possibility of Oumuamua being a “light sail”, or a piece of technology designed by hypothetical aliens to propel itself using solar radiation. Light sails could be used for transportation of cargo, or they could simply be debris or non-functional pieces from other projects. Although we are working on developing this technology right now, the authors of this paper have raised the possibility of alien civilizations having already produced these spacecraft.

Despite the widespread excitement over this article, not everyone feels the same way about our extraterrestrial visitor. The paper has met considerable backlash for not having nearly enough evidence to make such an extraordinary claim. Many have refuted its main arguments with facts of their own, but unfortunately, as Oumuamua is the first in its field, we have no way of knowing yet whose speculation is correct, if any.

Aliens, or lack thereof, has long been a hotly contested topic among scientists. The Fermi Paradox, devised in 1950 by physicist Enrico Fermi, poses the question of where everyone else in the universe is; for decades, we have been debating this very issue. Some speculate that among billions of stars, there’s no possible way we can be the only form of intelligent life. Others claim that since we haven’t figured out interstellar travel yet, aliens may simply share that frustration. Finally, some believe that aliens have visited our planet, either before humans existed or without us taking notice.

Although sometimes the search for extraterrestrial life can seem fruitless or disappointing, phenomena like Oumuamua serve as a fascinating reminder of everything we have yet to discover. We have no idea what might float through our solar system next, but for now, we’ll just continue to gaze at the stars.

What’s? Oumuamua

Hawaiian ‘oumuamua, meaning ‘scout’ (from ‘ou’, meaning ‘reach out for’, and mua, reduplicated for emphasis, meaning ‘first, in advance of’)