If there’s one story that left astronomers truly scratching their heads in 2018, it had to be the mysterious interstellar visitor known as Oumuamua. The odd cigar-shaped object flew through our Solar System in late 2017, and researchers spent much of last year just trying to figure out what the heck it was.

Theories are many, and scientists have suggested the usual suspects including a comet or asteroid, as well as more “out there” possibilities like an alien ship or probe. Now, one veteran astronomer is offering an entirely new theory, and he thinks he might have the evidence to back it up.

Thus far, all the talk surrounding Oumuamua has centered on the object being a solid chunk of something. Rock, ice, a mixture of the two, or maybe a rigid alien probe scanning the Solar System and reporting back to its handlers elsewhere. Zdenek Sekanina, a seasoned skywatcher with more credentials than you can shake a stick at, just submitted a new paper that suggests it wasn’t a solid object at all.

Rather than a solid rock or chunk of debris, Sekanina explains that Oumuamua might be “a monstrous fluffy dust aggregate released in [a] recent explosive event.” The cloud of dust, swirling and spinning as it travels through space, would account for some of the body’s more peculiar characteristics as observed by astronomers.

One thing that researchers haven’t been able to explain about Oumuamua is that it seems to be speeding up as it travels away from the Sun. That shouldn’t happen to a body like an asteroid, which led some to consider the possibility that it was an alien craft with some kind of propulsion system or “sail” that allowed it to accelerate due to solar radiation pressure.

A mass of dust and gas may behave the same way, and it’s a more down-to-Earth theory than Oumuamua being a recon vessel from an extraterrestrial civilization. Sekanina notes that additional research is obviously warranted, but this is a new wrinkle in the Oumuamua saga that could prove to be the answer researchers have been searching for.

Mike Wehner has reported on technology and video games for the past decade, covering breaking news and trends in VR, wearables, smartphones, and future tech. Most recently, Mike served as Tech Editor at The Daily Dot, and has been featured in USA Today, Time.com, and countless other web and print outlets. His love of reporting is second only to his gaming addiction.