Scientists are scratching their heads over some odd features found on the surface of Mars that have been likened to 'stick figures.'
The puzzling formations were photographed, appropriately enough, by the Mars Curiosity Rover and shared by the space agency last week on Twitter.
In the post, NASA mused that the quarter-inch long curiosities could be crystals or "minerals that filled spaces where crystals dissolved away."
One astrobiologist who studied the image proposed that they could be trace fossils of some kind, but their incredibly small size suggests that may be unlikely.
Another possibility put forward by a planetary scientist is that the anomalies are remnants of worm burrows that have become fossilized over time.
For now, NASA remains uncertain as to the origin of the oddities, but further examination of the 'figures' should hopefully provide additional insight into the mystery.
Until then, though, the space agency can take pride in beating Mars anomaly hunters to the punch by producing the first weird find from the Red Planet in 2018.
Source: Space.com