Astronomers discovered ‘Oumuamua, the first known interstellar object to visit our solar system on October 19, 2017. But is it an alien spacecraft?
The strange appearance of ‘Oumuamua, red, elongated and cigarlike, led some people to speculate that it could be an alien spacecraft. The new research suggests it is actually a natural phenomenon of another kind.
Matthew Knight, an associate research scientist in the University of Maryland Department of Astronomy who co-led the study, commented: “We have never seen anything like ‘Oumuamua in our solar system. It’s really a mystery still. 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.”
The astronomers formally named the object 1I/2017 U1 and gave it the common name ‘Oumuamua, which roughly translates to “scout” in Hawaiian.
The difficulty of classifying the interstellar object
According to the University of Maryland, researchers from around the globe tried to collect as much data as possible before it travelled beyond the reach of telescopes, which meant they only had a few weeks of observation.
Knight explained: “The motion of ‘Oumuamua didn’t simply follow gravity along a parabolic orbit as we would expect from an asteroid. 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.”
The study authors conclude: “We find that in all cases, the observations are consistent with a purely natural origin for ‘Oumuamua.”
Future interstellar visitors
Knight added: “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. We may start seeing a new object every year. That’s when we’ll start to know whether ‘Oumuamua is weird, or common. If we find 10-20 of these things and ‘Oumuamua still looks unusual, we’ll have to reexamine our explanations.”
Source: University of Maryland