Asteroid 1998 KY26 has scientists genuinely puzzled after it started accelerating in ways that just don't add up with what we know about gravity.
It's only about 11 meters wide, but this little rock is causing a big stir.
Aerospace engineers Korbin Hansen and Masatoshi Hirabayashi at the Georgia Institute of Technology checked if it might be a "dark comet" (basically, an icy object), but their models show it's way too warm for any ice to survive.
KY26 considered dehydrated, Hayabusa2 planned 2031
Turns out, KY26 is now considered a "dehydrated asteroid," meaning it lost its water long ago, so the ice theory is out.
Meanwhile, Harvard astronomer Avi Loeb tossed out a wild idea: maybe this isn't even an asteroid, but the lost Soviet spacecraft Phobos 1, pushed along by sunlight!
We'll have to wait for answers, though: the Japanese Hayabusa2 mission plans to visit in 2031 and could finally solve the mystery.