'Oumuamua interstellar object isn't an alien ship, but mysteries remain

'Oumuamua, the first known interstellar object to pass through our solar system, probably isn't an alien spaceship, a new study concludes. That doesn't mean the mystery is over, however, with the same study citing oddities that have left scientists baffled, including the object's unusual spin pattern and cigar-like shape. The findings were recently published in the journal Nature Astronomy.

READ: 'Oumuamua study finds interstellar object may be alien probe

'Oumuamua, which is officially named 1I/2017 U1, was spied by astronomers in October 2017. The object was identified by the Haleakaka Observatory at the University of Hawaii, but it couldn't easily be described due to its unusual characteristics.

The object shows signs of being both a comet and an asteroid, yet can't be solidly identified as either. Researchers describe 'Oumuamua's movement through space as being like a soda bottle spinning on its side on the ground.

The new study's co-leader Matthew 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.

Late last year, a study out of Harvard University caught the public's attention in a big way — it said it was possible the interstellar object may have been an alien probe of some variety sent this way to observe our solar system, possibly even Earth itself. This latest study dashes that exciting potentiality, however, finding that 'Oumuamua is probably some variety of naturally occurring space rock.

Knight explained:

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 latest analysis looked at existing data on the interstellar object, of which there isn't much due to 'Oumuamua's brief presence near Earth. This study has been called the first comprehensive analysis of the object, and it involved experts from all over the world. The team expects to see other interstellar objects appear in the future, potentially help answer questions related to 'Oumuamua's many persisting mysteries.