Geminids
The Geminid meteor shower (commonly known as "shooting stars") happens every year around December 14.
The Geminids have an activity rate of over 120 meteors per hour and a speed of 35 kilometers per second for several days, making them one of the most active showers of the year along with the January Quadrantids and August Perseids. After the Geminids, the next meteor showers will be the Comae Berenicids on December 19 and the Ursids on December 22. Both will have a much lower activity rate than the Geminids, between 3 and 10 meteors per hour.
The Geminids are visible from all over the northern hemisphere between December 4 and 17 approximately. Their peak of activity will take place on the nights of December 13 and 14, when we will be able to observe up to 150 shooting stars per hour.
What to expect in 2023?
2023 will be an excellent year for observing the Geminids, since the peak of their activity will occur one day after the new Moon (the new Moon will take place on December 13).
The maximum activity of the shower is expected to take place between December 14 and 15. The thin crescent Moon will allow the meteors to be observed in excellent conditions throughout the night.
Why do they happen?
The origin of the Geminids was a mystery for centuries because the meteor shower was not associated with any known periodic comet. In 1983, the infrared space telescope IRAS (launched by NASA) identified an asteroid, called Phaeton, and by studying its orbit, it was concluded that it was this asteroid that caused the meteor shower. This is therefore a peculiar case, since practically all other known meteor showers are caused by comets.
Astronomers speculate that Phaeton may be an extinct comet today and that the fragments that form the Geminids may have been detached centuries ago, when Phaeton still had cometary activity. As every year at this time, the Earth passes through a ring populated with those fragments detached from Phaeton. When one of those fragments (or meteoroids) comes into contact with the Earth's atmosphere, it is burnt by friction with the air, creating the luminous glow that we know as a meteor or shooting star. Typically, the most common meteors that we observe with the naked eye produce particles a few millimeters to a few centimeters in size that burn up in the atmosphere at about 100 kilometers in height.
The corresponding meteor shower seems to have a single center of origin, a point from which all shooting stars seem to emerge. This point is called "radiant" and its location is used to name the meteor shower. Thus, the Geminids have their radiant in the constellation of Gemini.
The 'radiant' of the Geminids.
How to see the Geminids?
They can be observed from any location as long as it provides a dark sky. It is preferable to observe from a place that has few obstacles that limit our sight (such as buildings, trees or mountains), and not to use optical instruments that reduce our field of vision. Even though the Geminids seem to come from the constellation of Gemini (hence their name), they can be seen anywhere in the sky. It is advisable to look at the darkest areas, in the opposite direction to the position of the Moon if the observation is made before it sets. The most comfortable strategy is to lie down and wait for your eyes to get used to the darkness.