TechGeminids' source questioned. Astronomer believes popular shooting stars aren't sun-born

Geminids' source questioned. Astronomer believes popular shooting stars aren't sun‑born

Close-up of a meteorite
Close-up of a meteorite
Images source: © Adobe Stock

10:41 AM EST, December 15, 2023

The Geminids have been observed for nearly 200 years, but it was only in the last decade that a NASA probe traced their formation. They typically consist of cosmic debris, which is produced under the influence of the sun. Astronomer Qicheng Zhang, however, argues that this phenomenon may have been mistakenly linked to the Geminids.

The prevailing theory behind the formation of the Geminids

The general belief is that the Geminids are fragments of the asteroid 3200 Phaethon. This space rock passes through the solar system and, interestingly, it is not expected to be a source of cosmic debris. However, this object is special as it develops a tail worthy of a comet.

3200 Phaethon appears near our planet just after it encounters the sun. This close encounter leads to severe thermal erosion on the surface of the asteroid. The intense solar radiation causes the asteroid to disintegrate, creating a cloud of fragments.

This material doesn't remain in place and travels behind the asteroid like a comet's tail. Hence, the swarm of Geminids reaches the Earth and collides with our atmosphere. The views are spectacular due to the brightness of the falling meteors that deeply penetrate the atmosphere. Despite its splendor, the theory of a solar origin does not convince all scientists researching the Geminids.

The mystery of the Geminids calls for a space expedition

Astronomer Qicheng Zhang maintains that several aspects of this theory may be incorrect. During the Geminids' activity, over a ton of cosmic debris hits our planet. However, the tail that the asteroid obtains from encountering the sun is estimated to provide only about ten kilograms of cosmic dust and rocks.

Unsatisfied, a team of astronomers decided to reevaluate the formation of asteroid Phaethon's tail. They directed the coronagraphs of the SOHO solar probe at it when it approached the sun in 2022. Their observations concluded that the forming cloud is primarily composed of gaseous sodium.

The cloud contains no rocks or dust, which suggests that the Geminids are not born from the sun. They could instead have originated from minor collisions occurring close to the Earth. This hypothesis suggests that the asteroid is extremely brittle and that the potential source of the Geminids needs further research.

To meet this demand, JAXA has taken up the task of designing a mission plan for the DESTINY+ probe. The Japanese plan to launch it into space in 2025, with one of its objectives being a close observation of object 3200 Phaethon. This endeavor might finally illuminate the baffling mystery of the Geminids' formation.

Image from the SOHO probe with an orange filter. It detects sodium, and it shows the brightly shining asteroid 3200 Phaethon.
Image from the SOHO probe with an orange filter. It detects sodium, and it shows the brightly shining asteroid 3200 Phaethon.© spaceweather
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