During the night you will not only see stars in the sky but many other objects:
- The Moon: every month, for about 25 days, the Moon is visible in the sky, forming a crescent, sometimes oval (gibbous) or in the form of a Full Moon. When you do not see her anymore, there are two explanations: either she gets up later or has already gone to bed, or she is the New Moon and she is hidden in the light of the Sun.
- Planets: early in the evening you can observe Mercury and Venus near the western horizon, sometimes accompanied by the moon, but they disappear quickly and you will not see them in the middle of the night. On the other hand you will be able to see Mars, Jupiter, Saturn and sometimes Uranus if the sky is very dark. Jupiter and Saturn shine much stronger than the stars while Mars shines with an orange light.
In general you recognize the planets to their brilliance and because they do not twinkle like stars because of their apparent disc. If they twinkle it’s because the air in the atmosphere is turbulent and distorts the images.
The planets revolve around the Sun and move slowly over the months across the sky. One evening you can see Jupiter above the eastern horizon for example and a few months later it will already be on the South side. The further the planets are from the Sun, the more slowly they move in the sky and Pluto, for example, can stay in the same region of the sky for more than a year.
Obviously the planets are tiny with the naked eye and look like stars. You will see them much better if you can observe them in a telescope or telescope with a magnification of at least 150 times.
- Airplanes: you will recognize them thanks to their flashing red and green lights. Sometimes they fly so high that you do not hear them.
- Artificial satellites: you will see small dots like stars slowly crossing the sky in silence in less than 15 minutes. Some will blink from time to time as they turn on themselves and reflect sunlight from different angles. If you look at the sky for a long time you can see several in the space of a few minutes because there are several hundred still operational and several thousand others that no longer work but are still orbiting the Earth.
- Shooting stars: all of a sudden, coming from nowhere, a more or less brilliant object can cross the sky and disappear a few seconds later. It’s a dust no bigger than a grain of sand that has entered the atmosphere and burned. In general shooting stars that we call meteors never make noise. Several times in the year, you can see the rains of shooting stars and see dozens in one night, they are the meteor swarms.
- The Milky Way: it is a band a little clearer that crosses the sky between the constellations, very visible near the Swan and Sagittarius. This is our Galaxy profile view. But you need a dark, moonless sky to watch it. We will come back to it.
- Polar auroras: difficult to observe in Europe and at low latitudes, it happens sometimes, when the Sun ejects a lot of matter in the space that the sky lights up with red or green during the night in the direction of the magnetic pole , towards the North-West. It is a very spectacular colorful phenomenon that changes shape in the space of 5 minutes. You will have a better chance of observing them in Finland, Canada or Alaska.
You’ve already heard about nebulae and galaxies. Most of these objects are located far too far in the universe to be visible to the naked eye. They are very very pale and there are very few that you can see with the naked eye: the globular cluster of M13, the Andromeda galaxy M31, the Orion nebula M42, and the two open clusters Praesepe M44 and the M45 Pleiades. But there are thousands of others.
Binoculars 10×50 or larger will allow you to see the brightest celestial objects a little closer but their image will remain very small and very pale. Here too you have to use a telescope or a telescope to see them clearly and to distinguish their shape.
If you are interested in nature watching, you can also observe nocturnal birds and animals such as owls, bats or small insects like moths during the night.