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Why a Rock From Another Solar System Has People Talking About Aliens

Another Solar System

The interstellar asteroid from another solar system known as ‘Oumuamua has people suspecting that it might have been sent by aliens.

Last year, an interstellar asteroid that came from another solar system passed by the sun, then soon after the Earth. It was a small object, difficult to track, moving at irregular speeds. A closer examination of the object has led to some big speculation about the nature of the rock, even leading to some respected researchers putting forward the idea that it is a piece of alien technology.

A recent paper from Harvard University’s Smithsonian Center for Astronomy, written by Shmuel Bialy and Prof. Abraham Loeb, offers a few eye-opening ideas on the nature of asteroid 1I/2017 U1, aka “’Oumuamua” (in Hawaiian the name means “a messenger that reaches out from the distant past”). The rock is believed to have come from another solar system, making it the first observed object to have entered our system from another. It also shows some features commonly associated with both an asteroid and a comet but doesn’t completely conform to either. It gets weirder from there.

A Cigar Shaped Anomaly

The object’s discovery was first announced on October 2017 by the Pan-STARRS 1 telescope, located in Hawaii. Since then, astronomers have been trying to understand it. They initially classified it as a comet before changing their minds and labeling it an asteroid, but neither tag fit. Instead, they determined that it was unique, and a new class of “interstellar object.”

‘Oumuamua is an elongated dark-red object, similar in shape to a cigar. It’s 10 times as long as it is wide, and traveling at speeds reaching 196,000 mph while spinning rapidly. Prior to its official announcement, researchers found that on September 9, 2017, it passed by our sun at a distance of about 0.25 AU (an AU is the distance from the Earth to the sun), then by Earth at a distance of 0.15 AU a few months later.

The object appeared to have a high density, which indicated a rocky, metallic composition. A closer look showed ‘Oumuamua was icier than previously thought, and a few final images of it from the Hubble Space Telescope revealed a few additional facts – and some new questions as well.

The Hubble images showed that ‘Oumuamua increased in velocity, defying the expectations of the researchers. The initial hypothesis was that the rock was venting material due to heat from the sun, a process known as “outgassing.” This process is how comets gain speed, but there’s a problem with that theory.

A New Old Idea

In their paper, Bialy and Loeb raise the question of why ‘Oumuamua experienced outgassing on the way out of the solar system, but not when it passed by the sun? If solar heat were the cause of the rock’s velocity, it would stand to reason that evidence of outgassing would have been observed earlier. According to the duo, outgassing should have also produced a rapid evolution in the rock’s spin, but that was not observed.

Instead, Bialy and Loeb offer the possibility that ‘Oumuamua is a piece of alien technology. Its movement and speed could show that the rock is actually a “lightsail” (aka a “space sail”), a form of spacecraft that uses radiation pressure for propulsion. It’s similar to some of the proposed spacecraft that may propel probes to neighboring systems to examine potentially habitable planets – something Loeb would know well as the head chair of the Breakthrough Starshot Advisory Committee, a group working on lightsails for exactly that purpose.

“We explain the excess acceleration of `Oumuamua away from the Sun as the result of the force that the Sunlight exerts on its surface,” wrote Loeb. “For this force to explain measured excess acceleration, the object needs to be extremely thin, of order a fraction of a millimeter in thickness but tens of meters in size. This makes the object lightweight for its surface area and allows it to act as a light-sail. Its origin could be either natural (in the interstellar medium or proto-planetary disks) or artificial (as a probe sent for a reconnaissance mission into the inner region of the Solar System).”

Loeb and Bialy calculated the presumed shape, thickness, and mass-to-area ration that an artificial object the size of ‘Oumuamua would need. They also looked at whether or not it could withstand interstellar flight. Their findings suggest that the rock would need a sail only a fraction of a millimeter thick to survive a journey through the galaxy and protect it from both tiny objects like dust and gravitational forces.

So if that is true and ‘Oumuamua is an artificial object, what is it doing here? The paper has ideas on that as well.

An Ancient Relic or Something More

In a separate article, Loeb suggested that ‘Oumuamua might be a relic of an ancient society that floated into our solar system – in other words, space junk. Another slightly “sexier” theory is that it is a probe sent to look at Earth. Researchers observed the rock for any signals it might be putting out and found nothing, but that doesn’t negate the theory.

Another Solar System

“[I]magine that `Oumuamua was on a reconnaissance mission,” said Loeb. “The reason I contemplate the reconnaissance possibility is that the assumption that `Oumumua followed a random orbit requires the production of ~10^{15} such objects per star in our galaxy. This abundance is up to a hundred million times more than expected from the Solar System, based on a calculation that we did back in 2009. A surprisingly high overabundance, unless `Oumuamua is a targeted probe on a reconnaissance mission and not a member of a random population of objects.”

To further back up this idea, he cites ‘Oumuamua’s close pass of Earth, and suggests it may have even corrected its trajectory at some point to take a closer look using unknown methods. He goes on to state that ‘Oumuamua may be one of many probes that have passed by Earth without our noticing. It was little more than luck that helped us identify this object, so others may have been here before and others might come in the future.

Of course, Loeb and Bialy’s research has already drawn plenty of criticism.

Looking for Another Solar System

“I am distinctly unconvinced and honestly think the study is rather flawed,” Alan Jackson, a fellow at the Centre for Planetary Sciences at the University of Toronto Scarborough wrote in an email obtained by CNN. “Carl Sagan once said, ‘extraordinary claims require extraordinary evidence’ and this paper is distinctly lacking in evidence nevermind extraordinary evidence.”

Jackson published a paper of his own about ‘Oumuamua for the Royal Astronomical Society in March 2018, where he addressed the idea that the object may have a solar sail. He cites its spectral data and notes that it looks like an asteroid or comet, and a light sail would have a much different look. Loeb and Bialy address this by suggesting the sail could potentially be covered in interstellar dust, but Jackson refutes this as well.

“Any functional spacecraft would almost certainly retract its solar sail once in interstellar space to prevent damage,” Jackson said. “The sail is useless once away from a star so there would be no reason to leave it deployed. If it was then deployed again on entering the solar system it would be pristine. Even if it was left deployed the dust accumulation would be primarily on the leading side like bugs on a windshield.”

He also goes on to state that ‘Oumuamua’s rotation wouldn’t match an object with a solar sail – even a damaged one, and an object with a  solar sail wouldn’t be able to change course once it was in motion. That means that we should be able to extrapolate where ‘Oumuamua came from, but so far there is no obvious origin for it.

“The thing you have to understand is: scientists are perfectly happy to publish an outlandish idea if it has even the tiniest ‘sliver’ of a chance of not being wrong,” astrophysicist and cosmologist Katherine Mack tweeted. “But until every other possibility has been exhausted dozen [sic] times over, even the authors probably don’t believe it.”

Alien or Not, the Research Continues

Alien technology or not, ‘Oumuamua is unique, which makes it of interest to astronomers everywhere. It displays unusual properties that don’t quite fit with that of a comet or an asteroid, and unlike all known objects that have passed through our system to date, it comes from beyond our solar system, well beyond the Oort Cloud where comets originate. That isn’t to say that it is the first object to come from another system, it’s just the first recorded.

Where it comes from and the type of system that it once called home are as interesting a topic to many as the possibility of it containing a solar sail. Jackson believes that it came from a binary star system that contained two stars, but that can’t be confirmed.

‘Oumuamua has passed beyond the range of our telescopes, but that won’t stop researchers from analyzing it for years to come. It will also have astronomers on the lookout for similar objects passing through our system.



Founder and DBP boss. Ryan likes the Kansas Jayhawks, long walks on the beach, and high fiving unsuspecting people.