There are other possible explanations. Previous research found that sunlight hitting KY26 and heat escaping from its surface could produce the extra push without buried water.

Another group of researchers, however, has explored a far more unusual possibility.

Harvard astrophysicist Avi Loeb and researchers Adam Hibberd and Adam Crowl have examined whether KY26 could actually be Phobos 1, an unmanned Soviet spacecraft that stopped communicating while traveling to Mars in 1988.