For some time now, Phaethon, an asteroid, has been perplexing astronomers. When it comes closest to the sun, a long tail of material is visible leaving the three-mile-wide (five-kilometer-wide) rock. However, if Phaethon’s tail consists of usual comet ingredients like ice and carbon dioxide, it should also be visible when the comet is as far away as Jupiter. But it’s not.
So, scientists have come up with some theories about Phaethon’s composition that could explain what trails behind when the asteroid passes the Sun. A new study has revealed that the infrared emissions of Phaethon analyzed by NASA’s Spitzer space telescope resemble emissions of meteorites in laboratories, suggesting Phaethon belongs to a rare class of meteorite, of which only six specimens are known.
Phaethon’s emission spectrum corresponds to a type of meteorite called the “CY carbonaceous chondrite,” distinguishing it from other well known asteroids like Ryugu and Bennu. This suggests that Phaethon had a unique origin, showing signs of drying and decomposition due to heating, along with a high iron sulfide content.
Analyses of Phaethon’s emission spectrum indicated olivine, carbonates, iron sulfides and oxide minerals, all of which supported the space rock’s connection to the CY class of asteroid. The researchers were able to demonstrate how temperatures encountered when passing by the sun might affect minerals in the asteroid, leading to the production of gases and small dust particles that form Phaethon’s tail as it passes by the sun. This research has contributed to a better understanding of the behavior of this mysterious cosmic object.
Continue reading about this fascinating discovery here.