Solving the Mystery of Asteroid Phaethon's Comet-like Tail.

Astronomers observing the asteroid Phaethon, which gives us the Geminid meteor shower every year, have found that its comet-like activity is caused by the emission of sodium atoms, not dust as previously thought. The discovery was made using the Solar and Heliospheric Observatory (SOHO) telescope, which recorded a two-hour sequence of Phaethon on May 15, 2022, as it made its closest approach to the sun. The findings could help shed light on the origins of the Geminids and suggest that other sun-skirting "comets" may actually be rocky asteroids like Phaethon heated up by the sun.