How to observe this rare alignment of 6 planets?

This week, from January 20 to 25, 2025, from sunset, an alignment of 6 planets will be visible in the night sky. A rare phenomenon which concerns Venus, Mars, Jupiter, Saturn, Uranus and Neptune. Based on the recommendations of the Côte d’Azur Observatory and NASA, we explain how to achieve the best observation conditions.

1. Stay away from light

It is in a dark sky, free of light pollution, that you will have the best chance of seeing the planets. Some stars and planets only give off a dim glow and will not be visible if you are too close to the city. According to NASA, we must move away from “ at least 20 to 30 miles (30 to 50 kilometers) from the city limits “. In France, there are 5 reserves suitable for observing a starry sky, recorded by the Côte d’Azur Observatory:

• the “Alpes Azur Mercantour” territory,
• the Cévennes national natural park,
• the Vercors regional natural park,
• the Millevaches regional natural park in Limousin,
• the Pic du Midi de Bigorre

2. Consider the phase of the Moon

You wouldn’t necessarily suspect it at first glance, but the phase of the Moon has an impact on the visibility of the stars. When it is full, it gives off a lot of light. By the same effect as light pollution, this intense light eclipses other stars which shine less brightly.

According to NASA, “The best time for stargazing is the two weeks before and after the new moon phase. On these evenings, the Moon is either absent from the sky all night, sets a few hours after sunset, or does not rise until the predawn hours ».

3. Use a red light to guide you

To observe the sky in the best conditions, the goal is for it to be as dark as possible. But how do you find your way on dry land? The white light of conventional torches should be banned because it has the effect of “blinding”. Your eyes will therefore have to take time to adapt to the darkness, which can take up to 20 minutes. The best solution? Use a lamp with low brightness such as red light lamps.

4. Use a sky map to find your way

While it is exciting to imagine witnessing a rare stellar phenomenon, it is often frustrating not to be able to find your way in the sky. To help you in this stellar quest, there are several applications downloadable to your smartphone.

5. Twins are your friends

Four of the six planets will be visible to the naked eye: Venus, Mars, Jupiter and Saturn. However, Uranus and Neptune are too far from Earth and do not emit enough light to be observed without magnification. So bring binoculars to have a chance of seeing them!

6. Choose your location wisely

These are details, of course, but they can make the difference and allow you, when combined, to have a great view of the stars. According to NASA, being at a higher altitude allows you to be above mist or fog that could block your view.

Being close to a mountain can also be an asset. Indeed, the mountain will block part of the light emanating from the cities, and therefore allow you to observe a darker sky.

However, although being near a mountain helps block light pollution, try to have a clear view of the sky so you can fully observe it. We therefore avoid being in the middle of a forest or at the bottom of a valley.

Additionally, the direction in which you look will also affect the visibility of the stars. The goal is for there to be no center of light pollution between you and the path of the celestial object you are observing.

Finally, pay attention to the weather. If there are clouds that evening and observation is impossible, don’t panic! The planets will return to normal at the end of February and mid-August. Other alignments of planets observable from Earth should occur.