Phaethon asteroid stuns science with sodium tail – T3N – Digital Pioneers

This is how NASA animators imagine the asteroid Phaeton. (Graphics: NASA)

A team from Caltech has recordings of asteroid Phaeton from the Sun and Heliospheric Observatory (SOHO) from 2022. They investigated and found something surprising. Contrary to the assumption that the tail is made of dust, it appears to be made of sodium instead. This also raises questions about the origin of the Geminids. Recently, the “potentially dangerous asteroid” accelerated its rotation.

The Soho satellite contains a coronal vertebra that sends the colors of light emitted from the asteroid’s tail through various filters. In this way the chemical composition can be determined.

Result: the tail can be seen in a sodium-sensitive orange filter. In the blue filter that reveals dust, an invisible shadow. Various investigations, with data from other observatories as well, confirmed the scientists: “Based on three different lines of evidence, we were able to show that this brightness is caused by Na-ID emission and not by dust.”

The team also combed through old data from the SOHO telescope and discovered 20-year-old archive footage of Phaeton. They suggest that the asteroid is not the origin of the Geminids.

This meteor shower, by far the second strongest this year, is best seen from Earth around December 14th. The name comes from its proximity to the constellation Gemini (Latin: Gemini).

It was previously assumed that Phaeton released dust when it flew over the Sun and created Gemini. But if – as it has now been determined – it emits sodium, this thesis is shaky.

The team brings a possible origin into the discussion without extensively researching this thesis. It is conceivable that this part of Phaeton was cut off 1,000 years ago. This could have released an unusual amount of dust and rocks into space, creating the meteor swarm.

A similar theory was presented by NASA nine years ago. In 2024, the Japanese space agency Jaxa, in conjunction with DLR, wants to send the Destiny Plus space probe to the asteroid. This task should finally explain the origin of the Geminids.