The Orbit Tellerium is a model of the sun, earth and moon. The sun is simulated by a
light bulb in a parabolic reflector, which casts a strong light onto the earth and moon.
1. The earth spins on its axis at the same time as the Moon orbits the Earth and the Earth
orbits the Sun.
2. A Date Indicator disc clearly indicates which month / season is being demonstrated .
3. A hand adjustable and removable Moon
4. The Moon’s orbit and Earth’s daily rotation can be demonstrated individually or together.
5. Demonstration of day/night, seasons, shadows, eclipses, phases of the Moon and the
eclipse cycle - Clearly demonstrates why eclipses don’t happen every month.
How it works:
The user gently pushes the
structure with the model earth
and moon on it, around the sun.
This automatically turns the gears
so that the moon orbits the earth.
While the earth is pushed round
the ‘sun’ once, the moon orbits the
earth 12 1/2 times. The gears also
ensure that the inclined axis of
the earth is pointing in a constant
direction, in order to demonstrate
Day & Night Model
A small model of a person can be easily attached to the globe.
The light from the sun lamp is sufficiently strong for the person
to cast a shadow on the globe. As the globe is rotated, the
person will pass from daylight to night time; and his shadow
will be long in the morning, short at midday and long again
in the evening.
As the model earth is pushed round, the gears ensure that the earth’s axis is directed
constantly to an exterior point; so that if the northern hemisphere is tilted towards
the sun at the beginning, it will be tilted away from the sun by the time the earth has
completed half its orbit, i.e. 6 months later.
For these demonstrations, a smaller sphere is used to represent the earth instead of
the larger globe. The strong light from the sun lamp illuminates one side of the moon,
which shows the phases of the moon as seen from the earth. To show the cause of an
eclipse a card is mounted on the end of the handle.
The informative booklet accompanying the Tellerium offers details of how to demonstrate
these and other topics.