Ursids
The Ursid meteor shower is visible, in the northern hemisphere, between December 17 and 26. Its activity rate is modest, between 10 and 50 meteors per hour, with a speed of about 33 kilometers per second. Ursids usually go unnoticed because they are located between two meteor showers with a much higher activity rate, that of the Geminids, which reach their maximum one week before the Ursids, and that of the Quadrantids, which reach their maximum two weeks after the Ursids.
What to expect in 2023?
2023 will be a bad year for observing the Ursids, as their peak activity will occur four days before the full Moon on December 27.
The maximum activity is expected on the night of December 22-23. The crescent Moon, very close to the full Moon, will illuminate the sky for most of the night, so visibility conditions will be poor. The best time for observation will be in the hours around dawn, when the Moon disappears over the horizon.
The “radiant” of the Ursids.
Why do they happen?
The meteors of the Ursids are fragments of comet 8P/Tuttle, discovered in 1858. As every year around this time, the Earth passes through a ring populated with the fragments detached from comet 8P/Tuttle in previous passages near the Sun. When one of these 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.
All meteors in a shower seem to have a single point of origin. This point is called "radiant", and its location is used to name the meteor shower. Ursids have their radiant near the star Kocab in the constellation Ursa Minor.
How to see the Ursids?
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 Ursids seem to come from the constellation of the Ursa Minor (hence its name), they can be seen anywhere in the sky. It is recommendable to look towards 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.