Astronomers around the world are scrambling to study an object unlike anything they’ve ever seen: a chunk of rock and ice seemingly fired our way from another solar system.

Discovered on October 19, the object is several hundred feet across and is currently speeding away from us at more than 98,000 miles an hour. At that speed, the space rock is moving fast enough to outrun the sun’s gravitational tug—implying that it was never part of our solar system to begin with.

The find marks a historic first for astronomers studying how stars and planets form. Scientists had long expected that the process of planetary formation results in chunks of ice and rock that, when given a nudge, could be flung