Glorious Light Show in December: Geminids Meteor Shower

Every year, Stargazers and Astronomers around the globe have their gears ready for various celestial events, such as planet watching, messier marathons, Milky Way photography, Meteor Showers, Eclipses, etc. Starting from Quadrantids in early January to Ursids in late December, we have a diverse plethora of meteor showers happening. Recently, people witnessed the Leonids meteor shower, which happened to be in mid-November. Cosmic Screen is now ready to display another shimmering event, which is none other than the Geminids Meteor Shower, which has its peak in mid-December. So, start packing up the things required for meteor gazing.

(Geminid meteor shower as observed from northern hemisphere in December 2013), By Asim Patel - Own work, CC BY-SA 3.0 — (Geminid meteor shower as observed from the northern hemisphere in December 2013), By Asim Patel – Own work, CC BY-SA 3.0

For people hearing it for the first time, what is a meteor shower?

Meteors are streaks of light in the sky caused by dust and sand-sized rocks burning up as they hit Earth’s upper atmosphere at very high speeds – often over a hundred thousand kilometers per hour. Several meteors appear to radiate from one point in the sky at a particular date each year, due to the Earth regularly passing through them at that position in its orbit. On a typical night from a dark location, you might be lucky enough to see up to 10 meteors per hour. But when the Earth passes through the dusty debris that was left behind by a comet or an asteroid, you will be able to see quite a bit more activity in the sky. That’s what we call A Meteor Shower

Most of the meteors disintegrate while entering the Earth’s atmosphere and never hit the surface. The number of meteors falling can vary considerably; the meteor showers that produce 1000 meteors an hour e.g. Leonids, are called Meteor Outbursts or Meteor Storms. Meteor showers are named after the constellation or bright star with a Greek or Roman letter assigned, which is close to the radiant position from where meteors originate. For example, meteors emerging from the star Delta Aquarii are called Delta Aquariids.

What is a radiant point?

The radiant position is the point where the meteor showers appear to emerge. Yes, you heard it right! They appear to emerge; meteor shower particles travel in parallel paths with the same velocity. It’s just a matter of perspective; just like in railway tracks, they are parallel but appear to emerge from a single point from far away; similarly, meteors appear to become visible from that point.

The best time to watch Geminids?

Since Earth rotates on its axis, all background stars in the night sky move across the sky; hence, the radiant position or radiant stars appear to move across the sky against the other background stars. When the radiant star’s position while roaming in the sky is at its highest point, it reaches the observer’s sky. At that point, the sun will just be moving out from the eastern horizon. This is the main reason: the best meteor-gazing time is generally slightly before sunrise. The Geminids are considered to be one of the most spectacular meteor showers of the year, with the possibility of sighting around 120 meteors per hour at its peak, which is on December 13 or 14, depending on your time zone. This shower owes its name to the constellation Gemini because the meteors seem to emerge from this constellation in the sky. To watch this heavenly show, you need prior information, such as when and where it will exactly happen, so here below is the table for you to fetch the information:

When to watch:	Radiant rises a couple of hours after the sunset so can watch all night around peak dates of December 13 and 14
Radiant time	The highest is around 2 a.m. for all time zones.
Peak	15 December dawn, roughly around 5 am
Overall Duration	December 4 to December 20
Origin	3200 Phaethon, an Asteroid of 5.8 kms diameter
Constellation	Gemini
Radiant point	Castor (the second brightest star in Gemini after Pollux)
Nearest Moon Phase	This year (2023), the new moon is on 12 December, so the waxing crescent moon will fall during these times.
What special in 2023:	This year since new moon is very near to peak dates, the moonlight won’t be interfering with meteor bright trails.
Meteor count rate	Under no-moon conditions, in the dark sky, up to 120 Geminids per hour could be watched.

Discovery

The Geminid meteor shower was first observed in 1862, much more recently than the Leonid and Perseid meteor showers.

It is believed that 3200 Phaethon is the cause of it. This dormant comet, which was earlier regarded as an asteroid, was discovered through images taken by the IRAS (Infrared Astronomical Satellite) in 1983. After its orbit was calculated, astronomer Fred Whipple announced that it shares its orbit with the Geminid meteor shower and linked these two.

Meteors are usually thought to originate from the leftover bits of comets that orbit the sun. When these comets, which originate from the chilling outskirts of the solar system, approach the sun, they give out these bits, which later collide with Earth’s atmosphere when Earth’s orbit coincides with its trajectory and appear as dazzling lights show. A similar explanation can be expected for these showers.

Phaethon orbits the sun very close as compared to other asteroids, with a period of around 1.4 years. However, it’s still a mystery how exactly the asteroid material, or interior, is released into the meteoroid stream

3200 Phaethon gets close to the sun as much as ½ the distance as Mercury. Then, it moves farther apart by outpassing the orbit of Mars. During this, when meteor bits overlap with Earth in mid-December every year, we observe beautiful meteor showers.

Which locations are favored?

This shower is more visible in the northern hemisphere. However, it’s visible in the southern hemisphere too. Well, the basic requirement is that the place should be isolated from all light sources and as dark as possible. In India, the best places to watch out for these stunning light shows are nearby hills, forests, remote villages, etc. It depends more on how dark a place you can find for observing them, away from city lights & pollution.

What is so special this year?

This year’s Geminids meteor shower is going to be a special one. Since the new moon is very close to the peak date of this shower, it is very beneficial for us, as its light will not overpower the meteor light. Also, the young, waxing crescent moon will set early in the evening on those peak nights. Hence, without any cosmic obstacle, you can enjoy the light shows and cherish them for your whole life.

If you wish to witness this heavenly event, on December 14, the Amateur Astronomy Club is providing a great opportunity, especially for the people living in Mumbai, Thane, Pune Nashik, and nearby who wish to witness this dazzling event. Join us at Naneghat in Maharashtra, where overnight camping and stargazing sessions have been conducted by our club since year 2014. So, do not waste your time if you have already made up your mind to enjoy this event. Book your camping spot now through the link given below:

https://amateurastroclub.in/overnight-stargazing-sessions/geminids-2023/zing-sessions/geminids-2023

Also, do not forget to share your experiences with us from wherever you make it possible to watch the Geminids. Have clear skies!