Mysterious object moving through space could be lost Soviet probe as NASA weighs in on theory

The asteroid 1998 KY26 is accelerating in a way that gravity alone does not explain, prompting speculation that it could be the lost Soviet probe Phobos 1. NASA Administrator Jared Isaacman said he had seen no evidence that it is anything other than an asteroid or poses a threat to Earth.

A Georgia Institute of Technology study published in *Icarus* found KY26 is likely too warm for buried water ice to explain its motion. Researchers proposing the Phobos 1 theory say models of the probe’s shape and rotation fit observations, but stress that this is not proof; other research finds its composition consistent with a rocky asteroid. KY26 is about 36 feet wide and rotates once every 5.35 minutes.