Science

Interstellar Object Looks Like Spacecraft, So Astronomers Will Check It Out

It's probably not aliens, but this is absolutely worth a look.

by Alasdair Wilkins
ESO/M. Kornmesser

Spotted in October, the mysterious object known as ‘Oumuamua is the first known visitor to our solar system from elsewhere in the cosmos. And while it’s almost certainly a natural phenomenon, it just happens to look pretty much exactly like the ideal design for an interstellar spacecraft, so one of the top alien-hunting organizations has announced they are taking a closer look starting Wednesday.

Here’s what we know about ‘Oumuamua, which gets its name from the Hawaiian word for “scout.” It’s traveling through the solar system at as much as 196,000 miles per hour, which is so fast there’s no way it’s caught up in the sun’s gravity — a dead giveaway it’s from beyond. But what’s really unusual, even by the standards of something we’ve literally never seen before, is how long and thin it is, like a particular stretched-out cigar.

The object appears to be roughly 1,300 feet long but is likely about a tenth as wide. That could absolutely be a naturally occurring object, but it does resemble what some who have considered the mechanics of deep space travel have called the ideal shape for an alien spacecraft. That’s why the team at Breakthrough Listen — Russian tech billionaire and physicist Yuri Milner’s organization — set up to search the universe for signs of extraterrestrial life, is about to start monitoring ‘Oumuamua as it speeds away for any signs of technology.

“Oumuamua is now about 2 astronomical units (AU) away, or twice the distance between Earth and the Sun,” Breakthrough Listen’s Andrew Siemion said in a statement. “This is closer by a factor of 50-70 than the most distant human artifact, the Voyager I spacecraft. At this distance, it would take under a minute for the Green Bank instrument to detect an omnidirectional transmitter with the power of a cellphone.”

The odds are, of course, very low that ‘Oumuamua is some kind of alien probe. The reason it looks like a spacecraft at all is that researchers believe such a cigar shape would cut down on friction and damage from interstellar dust. This may be a kind of self-fulfilling prophecy: It’s got that unusual structure not because aliens designed it that way but because an asteroid naturally shaped like that is the most likely to survive undamaged in interstellar space long enough for it to reach our solar system for us to observe it.

Either way, this isn’t just the extraterrestrial equivalent of a wild goose chase. As Siemion explains, this is an opportunity for Breakthrough Listen to do some real, useful science.

“Oumuamua’s presence within our solar system affords Breakthrough Listen an opportunity to reach unprecedented sensitivities to possible artificial transmitters and demonstrate our ability to track nearby, fast-moving objects,” he said. “Whether this object turns out to be artificial or natural, it’s a great target for Listen.”

Observations are set to commence December 13 at 3 p.m. Eastern using the Robert C. Byrd Green Bank Telescope in West Virginia. The telescope will initially examine Oumuamua for 10 hours across multiple radio bands, offering new observations not previously gathered by other teams.

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