Science

Oumuamua May Not Be An Alien Spaceship But Interesting Nonetheless

Oumuamua May Not Be an Alien Spaceship
Image credit: European Southern Observatory / M. Kornmesser – NASA

Ever since the mysterious interstellar object with odd movement, ‘Oumuamua, was discovered in October 2017, some people suspected that it could be an alien spaceship, with detailed research detailing the possibility. However, a new study shows that ‘Oumuamua may not be an alien spaceship, but it still baffles scientists a great deal.

‘Oumuamua was initially spotted by the Panoramic Survey Telescope and Rapid Response System 1 (PanSTARRS1) a the University of Hawaii’s Haleakala Observatory. ‘Oumuamua roughly translates to “scout” in Hawaiian, but it’s also known by the name of 1I/2017 U1. Researchers rushed to try to collect as much data as possible, but it was difficult because it was soon out of reach for most of the telescopes on Earth.

The new study led by Matthew Knight, an associate research scientist in the University of Maryland Department of Astronomy, suggests that “Oumuamua has a purely natural origin.” The team published their findings in the journal Nature Astronomy.

“We have never seen anything like ‘Oumuamua in our solar system. It’s really a mystery still,” Knight said in a statement. “But our preference is to stick with analogs we know, unless or until we find something unique. The alien spacecraft hypothesis is a fun idea, but our analysis suggests there is a whole host of natural phenomena that could explain it.”

Scientists are particularly puzzled by its cigar-like shape, as well as strange trajectory pattern. Previously, it was suggested that the interstellar object may have retained that trajectory after being ejected from a binary star system. Scientists don’t know whether it’s an asteroid or a comet, because it shows properties of both, but ‘Oumuamua may not be an alien spaceship.

“The motion of ‘Oumuamua didn’t simply follow gravity along a parabolic orbit as we would expect from an asteroid,” Knight said. “But visually, it hasn’t ever displayed any of the cometlike characteristics we’d expect. There is no discernable coma — the cloud of ice, dust and gas that surrounds active comets — nor a dust tail or gas jets.”

“We put together a strong team of experts in various different areas of work on ‘Oumuamua. This cross-pollination led to the first comprehensive analysis and the best big-picture summary to date of what we know about the object,” Knight explained. “We tend to assume that the physical processes we observe here, close to home, are universal. And we haven’t yet seen anything like ‘Oumuamua in our solar system. This thing is weird and admittedly hard to explain, but that doesn’t exclude other natural phenomena that could explain it.”

Knight and his colleagues suggest that there could be more explanations as to how the interstellar object escaped its normal trajectory, since it could not be an alien spaceship. One theory suggests that it was ejected by a gas giant planet like Jupiter that orbited another star. It could be the result of a so-called Oort cloud – a huge shell of smaller objects located at the edge of the solar system. In that way, some objects could slip out of the star system away of the influence of the host star’s gravity.

Although ‘Oumuamua may not be an alien spaceship, Knight believes that our solar system is to host many more interstellar objects. Knight is particularly excited about the future data from the Large Synoptic Survey Telescope (LSST) which is planned to be operational in 2022.

“In the next 10 years, we expect to begin seeing more objects like ‘Oumuamua. The LSST will be leaps and bounds beyond any other survey we have in terms of capability to find small interstellar visitors,” Knight said. “We may start seeing a new object every year.”