NASA says Phaethon is stranger than astronomers thought

Asteroid 3200 Phaethon, a stranger in space, is stranger than astronomers thought, NASA researchers said Tuesday.

The asteroid behaves like a comet and astronomers thought its tail was made of dust, but… A new study published in The Planetary Science Journal I found that the tail was actually made of sodium gas.

Qicheng Zang, a PhD student at Caltech and lead author of the study, used the Sun and Heliospheric Observatory’s spacecraft to examine Phaethon and its tail. According to NASA, most asteroids made of rock do not form a tail as they approach the sun. Comets are made of rock and ice usually with tails.

Based on the Phaethon study, Zhang and other scientists wonder if some comets might not, in fact, be comets.

“Many of those other ‘comets’ swimming in the sun may also not be ‘comets’ in the usual sense of an icy body, but instead may be rocky asteroids like Phaethon that are heated by the sun,” Zhang said on a NASA website.

Phaethon is also a resource the annual Geminid meteor shower, Although comets cause most meteor showers. When astronomers thought Phaethon’s tail was made of dust, this made sense because burning bits of trail debris produce meteor showers. Now experts are left searching for the answer to how Phaethon, with its tail of sodium gas, supplied the material for the Geminid meteor shower each December.

Zhang’s team said there may have been a devastating event a few thousand years ago that caused Phaethon to eject the material that makes up the Geminid debris stream.

Researchers may have more answers later this decade. An upcoming JAXA mission called DESTINY+ is expected to fly by Phaethon to image its rocky surface and study any dust that may be present around the asteroid.

Phaethon It also caught the attention of NASA in 2017 when it got close enough to Earth that it was classified as “hazardous” by the International Astronomical Union’s Minor Planet Center.