Why don't we see the Geminids twice a year?

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Discussion Overview

The discussion centers around the visibility of the Geminid meteor shower, specifically why it occurs annually in December rather than also in November, despite Earth crossing the orbit of asteroid 3200 Phaethon twice a year. The scope includes theoretical considerations of orbital mechanics and the nature of meteor showers.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants note that the Geminids are visible due to fragments of asteroid 3200 Phaethon colliding with Earth's atmosphere, occurring around December 13-16.
  • One participant points out that the orbits of Phaethon and Earth are not aligned in November, suggesting that the conditions for visibility are not the same as in December.
  • Another participant raises the question of whether the debris from Phaethon is evenly distributed along its orbit, which could affect the meteor count.
  • There is a clarification regarding the classification of Phaethon as an asteroid rather than a comet, which some participants initially misidentified.

Areas of Agreement / Disagreement

Participants express differing views on the alignment of orbits and the distribution of debris, indicating that the discussion remains unresolved with multiple competing perspectives.

Contextual Notes

There are assumptions regarding the distribution of debris and the alignment of orbits that are not fully explored, leaving some questions about the conditions necessary for the visibility of the Geminids in November.

dmayers94
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We see the Geminids as a result of the fragments of the asteroid 3200 Phaethon colliding with the Earth's atmosphere. They are visible every year around December 13-16. As you can see in this NASA simulation (http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=Phaethon;orb=1), we pass through the orbit of the asteroid twice every year (around Dec. 14 and Nov. 1). The circumstances seem to be the same on both dates, so why is it that I don't hear about the Geminids in early November?
 
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Rotate the orbit diagram to see that the ex-comet's orbit doesn't actually intersect with the Earth's orbit twice.
In November the two orbits are not plane-aligned.
 
We may cross Phaeton's orbit twice a year, but Phaeton itself isn't always where we cross it. So why should the Geminids be? Or are they spread out evenly over the whole orbit?
 
Thank you Bandersnatch!
 
Michael Redei said:
We may cross Phaeton's orbit twice a year, but Phaeton itself isn't always where we cross it. So why should the Geminids be? Or are they spread out evenly over the whole orbit?
Yeah they're spread out, but not evenly. The meteor count each year varies due to this.
The meteors are just a bunch of debris following the same orbit that the asteroid from which it probably fell off.

Also, I've just noticed that Phaeton3200 is not only not a comet, but it's also not-gone, so my previous post shouldn't read "ex-comet" but "asteroid".
 

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