At https://spaceweather.com ….. archive, December 13th, 2023. This post concerns the Geminid meteor stream. Earth is currentlyt passing through this annual meteor shower, and the debris has been traced back to a small asteroid, 3200 Phaethon. A paper published this month in Planetary Science Journal is challlenging that view. It seems that 3200 Phaethon is not what it is cracked up to be.
The Geminids first appeared in the middle of the 19th century. Astronomers scoured the sky for the parent comet – but found nothing. Every year it re-appeared the issue would come to the fore once again. For over a 100 years they had no parent comet – until, in 1983, NASA found 3200 Phaethon. The consensus view quickly decided that it was most definitely the source of the meteor shower. Its orbit was a very close match with that of the Geminids, for example, and has been seen, on occasion, to sport a tail. The problem has always been that 3200 Phaeothon is supposed to be an asteroid. They are not supposed to produce meteor showers. However, in 2009, and again in 2012, NASAs STERIO spacecraft caught it sprouting a tail. Not much of one, admittedly, but it did seem to provide the proof that 3200 Phaethon was the source. The new research paper, by Qickeng Zhang et al has claimed that although the Geminid meteor shower is big – 3200 Phaethon itself is puny. Of little consequence. In direct contrast to the consensus. The asteroid is simply too small and is not capabe of producing so much debris, outgassed. Not only that but a 2022 view of the asteroid showed that the tail was made of gas. It was more like a comet coma rather than a trail of debris. The tail was actually made of sodium gas. Meteor showers are normally composed of rocky pieces, and dust as well as gases. Now, it would seem that astronomers have to look for a new progenitor of the stream. The Japanese are planning for a rendevous with 3200 Phaethon next year – or in 2025. They intend to look more closed at the surface of the asteroid.