Geminids: A punctual meteor shower

To sleep or not to sleep...

Every stargazer has had to ask this question at least once. But this December 14, the answer must be the latter; for The Geminids are back.

They have already kicked off on December 5 and will continue till December 17, but their peak on December 14 is the event worth watching. With >100 meteors per hour darting through our sky, it provides us with one of the grandest spectacles every year.

Why are the Geminids special?

Meteor showers find their origin in the dust grains released from comets. We observe the meteor shower phenomenon when the Earth moves through this debris.

But there is an exception, The Geminids; they are not caused by any comet but by an asteroid named Phaethon.

In studies performed by NASA in 2012, it was theorized that Phaethon's extremely close perihelion (point in an orbit closest to the sun) causes fractures to grow on the surface of the asteroid. These fractures can sometimes result in loosely held pieces being dislodged from the surface upon getting hit by solar radiation.

But a recent spectroscopic study suggests that as Phaethon approaches the sun, the sodium in it heats up and fizzes out of the asteroid but not before sending out a lot of rocky debris from the asteroid, which the feeble gravity of Phaethon can't stop.

Phaethon is an exciting entity itself, with it being the first asteroid that we have ever discovered using images from a spacecraft.

But the characteristic that makes it very interesting is its "comet" like nature. Since its orbit resembles a comet more than an asteroid, it has been referred to as a Rock Comet. Also, unlike most other asteroids that tend to be gray or red, Phaethon is one of the rarer blue-colored asteroids we have discovered.

The high-speed flyby mission by the JAXA (Japan Aerospace Exploration Agency) named DESTINY+ will help understand the nature and origin of these cosmic specs from Phaethon.

While we all plan to witness the Geminids in their full glory, humanity must look past their faithful appearance every year and try to get a feel for their mysterious origin, which ultimately makes us question the complexity of comets and asteroids, especially when their differences remain obscure.

Footnotes:

1. Quadrantids also have a non-comet parent body, with theirs being a minor planet

2. https://www.sciencedirect.com/science/article/abs/pii/S0032063319304969

3. https://www.isas.jaxa.jp/en/missions/spacecraft/developing/destiny_plus.html

4. https://answersresearchjournal.org/distinction-between-asteroids-comets/

Image credits: Wikipedia

- Kshitish Kumar Ratha (MS22174)