A weird asteroid has just gotten a little weirder.
We have known for a while that asteroid 3200 Phaethon acts like a comet. It brightens and forms a tail when it’s near the Sun, and it is the source of the annual Geminid meteor shower, even though comets are responsible for most meteor showers. Scientists had blamed Phaethon’s comet-like behavior on dust escaping from the asteroid as it’s scorched by the Sun. However, a new study using two NASA solar observatories reveals that Phaethon’s tail is not dusty at all but is actually made of sodium gas.
“Our analysis shows that Phaethon’s comet-like activity cannot be explained by any kind of dust,” said California Institute of Technology PhD student Qicheng Zhang, who is the lead author of a paper published in the Planetary Science Journal reporting the results.
Read more at NASA
Image: This illustration depicts asteroid Phaethon being heated by the Sun. The asteroid’s surface gets so hot that sodium inside Phaethon’s rock likely vaporizes and vents into space, causing it to brighten like a comet and form a tail.
(Credits: NASA/JPL-Caltech/IPAC)