Jon Solo Sebastian 11/14/2025:

With all the chatter going on about 3I Atlas, I thought it would be fun to circle back to 2017 when we had another interstellar visitor. If you followed any of that at the time, you might remember the speculation of alien visitors running rampant online—though that is nothing compared to the mass speculation of 3I Atlas. I’ll eventually dig into that one once we know a little more about it, but for today, meet Oumuamua!

If you’re like me and look at the night sky wondering what’s out there, or who is looking back down at us, then you might remember 2017 when we had a “visitor” from another solar system. Of course we couldn’t see it just by looking up at the sky, and only the most powerful telescopes in the world were able to pick it up even though it was huge. Oumuamua, which means: scout or messenger, is a large, reddish, cigar shaped structure or comet that is around one-quarter mile (400 meters) long.

Many theories began flying out the window like alien visitors… I feel like we, as a civilization, are absolutely craving confirmation of other beings existing out there. The theory most can agree on is that while it is considered ‘alien,’ the term is used as it being foreign to our solar system and that the object is some sort of comet or broken piece of a planet from another solar system that traveled through our system before moving on to God knows where. A theory I found interesting comes from Avi Loeb who calls it a solar sail that was built to carry a spacecraft across space. If you’re a Star Wars fan like me, you might be picturing the ship Count Dooku used in Attack of the Clones with the little solar sail pulling his ship along. It’s an interesting idea, but where is the craft it carried? Did it drop it off here, or a different solar system?

One of the many things that had scientists searching for answers was how the object suddenly accelerated. Folks often make the joke about aliens visiting Earth and then racing off because they think humanity is a little too messy for them. It makes me think of a scene in National Lampoons Vacation when the Griswolds are in a bad neighborhood and Clark tells the family to roll the windows up. While that could be possible, scientists theorized a fairly plausible explanation for Oumuamua’s need for speed.

With the increase in acceleration, many speculated Oumuamua must be an alien craft or probe. The acceleration is typically coupled with outgassing of material, which would in a sense cause the object to lose weight and pick up speed, but scientists and astronomers found no evidence of gas or a tail like a comet produces. The possibilities and speculations continue—some suggest the object is composed of nitrogen ice while others think it could be composed of hydrogen ice.

An astrochemist at the University of California, Jennifer Bergner, “wondered if it could just be a water-rich comet that got exposed to a lot of cosmic radiation. That radiation would release the hydrogen from the water. Then, if that hydrogen got trapped inside the ice, it could be released when the object approached the sun and began to warm up. Astronomers who observed ‘Oumuamua weren’t looking for that kind of hydrogen outgassing and, even if they had been, the amounts involved could have been undetectable from Earth.” She began investigating the possibility by running tests and doing various calculations. What she determined was that this could in fact account for the object’s acceleration. When the object gets warmer, it begins to sort of change structurally due to the ice melting. Pockets of gas are hidden under the ice, so once the ice melts away, the gas leaks into space, and gives the object a little bit of a boost.

While that is a plausible and likely possibility, it’s impossible to confirm without running tests, but Oumuamua is too far out of our reach now. Scientists, astronomers, and researchers have put plans in place to test any other objects that find their way into our solar system, but until we have the technology to go out there and catch one or land on one, we can only do so much testing and speculating.

One astronomer, Karen Meech, who was the team lead of the team who initially discovered Oumuamua, states most comets are bright, which allow for detection of gas. Oumuamua was not bright at all. This doesn’t mean it wasn’t a regular comet; it simply means the tools at their disposal might not have detected gas, or considering it’s from a different solar system, it could be throwing off unknown or undetectable (by us) gas or dust.

Most circles have given up on the idea of it being an alien spacecraft, but the idea of it being a solar sail used to carry craft is a very interesting theory. Either way, Oumuamua is fascinating and I hope we find more answers about it, or discover other interstellar objects to study.