The remains of Halley's Comet give way to the Aquariid meteor shower

GenevaThe shorter nights accompany the arrival of the summer constellations, and the visibility of the planets is spread out throughout the night. During this month, Mercury will be too close to the Sun to be easily observed. Venus will be visible in the early morning, although its apparent proximity to our star makes its observation difficult. Mars will continue to be visible during the first part of the night as an orange dot. Jupiter, meanwhile, will also be visible during the first half of the night, located in the constellation of Taurus. In the second half of the month, the gas giant will begin to hide in the light of the evening twilight. After a couple of months, Saturn will be visible again in the last hours before sunrise and will form a compact triangle with Venus and Neptune during the first days of May. The full moon on the 12th will be near the apex, the farthest point in its orbit around Earth, so it will appear 5% smaller and 10% less bright than usual.

The Aquarids meteor shower

This month we will once again be able to enjoy a spectacular meteor shower. This time, the famous eta-Aquarids will be taking place. The peak will be reached on the night of May 6th, with an average of about 30-40 meteors per hour, although the brightness of the Moon may make it slightly difficult to observe the faintest meteors. As their name suggests, the meteors appear to be coming from the constellation of Aquarius, although they can be observed anywhere in the night sky. This meteor shower is produced by the debris left behind by the passage of the famous Halley's Comet, visible from Earth every 75 years and which will make another close approach in 2061.

How many stars can be seen in the night sky?

Our galaxy, the Milky Way, is made up of about one hundred billion stars. A large number of them can be observed from Earth. The stability of the atmosphere can have a major impact on the number of visible stars. On the other hand, the most distant or faint stars have a brightness that our eyes are unable to detect.

Apparent magnitude is the parameter that indicates the brightness of stars observed from Earth. The more negative the magnitude, the brighter the star. For example, with an apparent magnitude of -1.46, Sirius, in the constellation of Ca Major, is the brightest star in the night sky. On the other hand, the North Star, which indicates the direction of north and is easily observed, has a magnitude of 2. Depending on visual acuity, the maximum magnitude our eyes can detect is between 6 and 7. In urban areas, the limiting magnitude is between 3 and 4. This translates to 250 stars being visible from neighborhoods with the least light pollution—one-tenth of the total number of stars that can be observed in a perfectly dark sky. When we move away from urban areas, the limiting magnitude is around 5 or 6, allowing us to observe thousands of stars and distinguish the structure of our galaxy.