Astronomers have spotted some kind of outer space rock that's the first visitor from outside of our solar system that they've ever observed.
The discovery has set off a mad scramble to point telescopes at this fast-moving object to try to learn as much as possible before it zips out of sight.
"Now we finally have a sample of something from another solar system, and I think that's really neat, " says Karen Meech, an astronomer at the University of Hawaii Institute for Astronomy, "and so you'd love to see if it looks like stuff in our solar system."
It's long been assumed that an interstellar object like this one should be out there, because giant planets in forming solar systems are thought to toss out bits of space crud that haven't yet glommed into anything. But this is the first time scientists have actually found one.