The asteroid Phaethon, often referred to as a ‘rock comet’, has been re-evaluated by the ESA/NASA SOHO observatory, which suggests that its brightness and tail result from sodium emissions rather than dust release, as previously believed. Phaethon orbits the Sun every 524 days, coming remarkably close at perihelion, which has historically tied it to the Geminid meteor shower. This meteor shower is unique as it lacks a known parent body, prompting speculation regarding Phaethon’s role when it was identified in 1983. Observations from May 2022 revealed Phaethon’s brightening attributed to sodium fluorescence when it nears the Sun, rather than the release of dust. Furthermore, this study indicates that Phaethon may share characteristics with other rocky objects, reshaping the understanding of what constitutes a comet. Additional theories posit that a disruptive event may have formed the Geminids over two millennia ago, while recent resurfacing could explain the sodium observed today. Future missions, including the JAXA DESTINY+ flyby in 2028, aim to delve deeper into Phaethon’s mysterious history. Citizen scientists continue to contribute to discoveries through SOHO, reinforcing the observatory’s legacy as a leading comet hunter.
