Observe the sky in real time in 3D. Observe the planets of the solar system, the Sun, the Moon, the constellations, the stars and the milky way. Navigate freely in the sky by clicking on the keys to move forward or backward in time, click on the buttons to display the names and shapes of the constellations. Discover the positions of the stars and display the azimuthal grid to find your way in the sky. The « screen » feature allows to take a photo of the sky and download the image.

JEUDI 15 OCTOBRE 2026 À 00:49 UTC+2

Real time observation of the starry sky

Visualize in real time the position of the stars in the sky.

Star chart

A star chart is a representation of the sky as it appears from a specific place and at a given moment.
Unlike a printed map, this interactive star chart updates in real time depending on your position and the date and time chosen.
It makes it easy to identify stars, planets and constellations.

Celestial objects

The observation of the sky allows to see different types of celestial objects such as planets, stars, constellations, galaxies or nebulae.
Some celestial objects such as the Moon, Venus and certain stars are visible to the naked eye. By contrast, deep sky observation requires the use of astronomical instruments such as telescopes.
In good conditions, it is possible to see at night with the naked eye about 3,000 stars as well as some planets.
Unlike the stars, the planets do not twinkle, which allows us to differentiate them.

The Sun: a giant star

The Sun is a star located at the center of the solar system, it exerts a force of gravity that keeps the planets in their orbits. The Sun is also our main source of light and heat, without which life on Earth would not be possible.

Inclination, rotation and revolution of the planets

In addition to revolving around the Sun, the planets also rotate on themselves. They rotate for the most part in the same direction as around the Sun except for some like Venus which turns in the opposite direction of its revolution.

Access the unique planet animations:

See the rotations of the planetsSee the revolution movements of the planets
MercureLearn more

The planet closest to the Sun. Small and rocky, it experiences extreme temperature differences between day and night.

Diameter : 4879.4 km | Inclination of the planet : 0.0352° | Inclination of the orbit : 7° | Rotation period : 58,6458 jours | Revolution period : 87.969 days
VénusLearn more

Almost twin to Earth in size, but covered with toxic clouds. It is the hottest planet in the solar system.

Diameter : 12103.6 km | Inclination of the planet : 177.36° | Inclination of the orbit : 3.39471° | Rotation period : -243,023 jours | Revolution period : 224.667 days
TerreLearn more

The only planet known to be home to life. Largely covered with water and protected by a favorable atmosphere.

Diameter : 12756.274 km | Inclination of the planet : 23.4366907752° | Inclination of the orbit : 0° | Rotation period : 23h 56min 4s | Revolution period : 365.256363 days
MarsLearn more

The red planet, famous for its iron-rich soil. It is home to the largest mountains and canyons in the solar system.

Diameter : 6792.4 km | Inclination of the planet : 25.19° | Inclination of the orbit : 1.85° | Rotation period : 24,622962 h | Revolution period : 686.885 days
JupiterLearn more

The largest planet in the solar system. A gaseous giant with a tormented atmosphere, it has a famous storm: the Great Red Spot.

Diameter : 142984 km | Inclination of the planet : 3.12° | Inclination of the orbit : 1.304° | Rotation period : 9h 55min 27,3s | Revolution period : 4332.01 days
SaturneLearn more

Known for her beautiful rings made of ice and rock. She is a gas giant like Jupiter.

Diameter : 120536 km | Inclination of the planet : 26.73° | Inclination of the orbit : 2.486° | Rotation period : 10h 33min | Revolution period : 10754 days
UranusLearn more

Icy giant with a blue-green hue due to methane in its atmosphere. It is tilted to the side, which makes it unique.

Diameter : 51118 km | Inclination of the planet : 97.8° | Inclination of the orbit : 0.77323° | Rotation period : -17,23992 h | Revolution period : 30698 days
NeptuneLearn more

The planet furthest from the Sun. Very windy and cold, it has a beautiful blue color and intense storms.

Diameter : 49528 km | Inclination of the planet : 28.32° | Inclination of the orbit : 1.77° | Rotation period : 16h 6,6min | Revolution period : 60216.8 days

The Moon, the only natural satellite of planet Earth.

The Moon is at an average distance of about 380,000 km and circles the Earth in 27.3 days.

Due to its synchronous rotation with the Earth the Moon always shows us the same face.

On its visible side there are 'lunar seas' which are large dark plains formed by ancient volcanic flows. There are also impact craters observed.

Its gravitational influence is responsible for the tides on Earth.

When the Moon passes in front of the Sun by masking it, it causes a phenomenon called solar eclipse which partially darkens the sky for a few minutes.

It takes on a reddish color during lunar eclipses: when it passes behind and finds itself in the shadow of the Earth and certain conditions are met.

Rotation and revolutionMoon phase

The Milky Way

The Milky Way is the galaxy in which our solar system is located. It gathers between 200 and 400 billion stars and forms a wide band of light visible in the night sky.

Positions of celestial objects in the sky in real time

We reproduce the sky with the constellations and their stars, the planets of the solar system, the Moon, the Sun and the Milky Way.
We accurately calculate and display their apparent positions in the sky in real time, taking into account :

  • local sidereal time of the selected observation location,
  • celestial coordinates of the stars, proper motion, precession, nutation and aberration of light,
  • date and time.

The celestial vault is delimited to reveal which celestial objects are currently visible in the sky.
The compass tells you which direction you are looking, you can select another city to observe the sky from its position.
Use the buttons to travel through time and observe how celestial objects move in the sky as the earth rotates.

Positions of the planets in the sky

Positions of the moons in the sky

Positions of constellations and stars in the sky

Deep sky

The deep sky is a set of celestial objects located outside the solar system.
It includes galaxies, nebulae, star clusters and quasars.
These objects are very far from the Earth and often low in brightness.

Galaxy astrophotographie

Observation equipment

Observing the night sky is a fascinating experience that allows discovering planets, stars, galaxies and nebulae visible from Earth.
To take full advantage of these observations, it is important to have the right astronomy equipment.

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Galaxy astrophotographie