Pocket planetarium

This pocket planetarium offers the opportunity to understand in a fun and educational way, many astronomical notions about the solar system. It is recommended for family use and scientific demonstrations. It's main advantage is that we can easily carry it and use it outdoors, day and night. It can be used as a tool for astronomy demonstrations. This is the missing link for understanding how the solar system moves.

Earth and ecliptic

In the initial position, the planetarium can locate the earth in its celestial environment (sky, zodiac, ecliptic).

Here, the earth turns on itself. Its axis of rotation is tilted 66.5° to the ecliptic plane.

Latitude

The planetarium is equipped with a graduation that allows to regulate the latitude in accordance with the latitude of the place we wish to observe. The range extends from 20° to 90° latitude.

The planetarium is here set to the average latitude of Europe, ie 47°. The vernal point is exactly in the east. It is 18 hours in sidereal time.

North Pole

The planetarium is here set at 90 degrees latitude, the North Pole. The Sun is above the local horizon. It revolves around the horizon in one day, always at the same height.

This side shows the latitudes of featured places: the North Pole, the Arctic Circle, the Tropic of Cancer, a few African capitals (Dakar, Casablanca) and also some European ones (Lisbon, Madrid, Paris, London, Berlin, Stockholm, Oslo) and Tromsø, the only university-city beyond the Arctic Circle in Norway.

Equinoxes and solstices at the North Pole

The planetarium is here set to the latitude of the North Pole. Four yellow pins indicate the four positions of the sun at the solstices and equinoxes. At the equinoxes (positions 1 and 3) the Sun is right on the skyline. At the summer solstice (position 2), the Sun is at its maximum height; it is the middle of the polar day. At the winter solstice, the sun is below the horizon; it is the middle of the polar night.

The markings on this side indicate the latitude in degrees. Here, the planetarium is set at 90 degrees latitude, the North Pole.

Equatorial plane and sidereal time

The planetarium has an equatorial disc indicating the sidereal time. It appears by transparency through the hemisphere. Here you see the wheel to rotate the globe, and on the side, the thumbscrew that secures the cradle.

The reading of the equatorial plane indicates that it is 0 hour in sidereal time. .

Ecliptic and Zodiac

The plane of the ecliptic, carried by the hemisphere, revolves around the motionless earth globe.

The colored pins on the ecliptic, simulate the motion of the planets. The yellow pin symbolizes the sun. One rotation of the ecliptic represents about a day.
The Zodiac is engraved on the plane, which embodies the ecliptic plane. The reading of the equatorial plane indicates that it is 12 hours in sidereal time.

Compass card

In this view from above, you can see the details of the zodiac and the compass card.

On the compass card, note that the origin of the azimuths is the south for astronomers, as opposed to navigators that use the north.