Solar System’s First Known Interstellar Visitor Likely A Cookie-Shaped Planet Shard
CAPE CANAVERAL, Fla. (AP) — Our solar system’s first known interstellar visitor is neither a comet nor asteroid as first suspected and looks nothing like a cigar.
A new study says the mystery object is likely a remnant of a Pluto-like world and shaped like a cookie.
Arizona State University astronomers reported this week that the strange 148-foot (45-meter) object that appears to be made of frozen nitrogen, just like the surface of Pluto and Neptune’s largest moon Triton.
The study’s authors, Alan Jackson and Steven Desch, think an impact knocked a chunk off an icy nitrogen-covered planet 500 million years ago and sent the piece tumbling out of its own star system, toward ours.
The reddish remnant is believed to be a sliver of…