12
Observing
Astronomical observations
The first observations should be performed during dusk so that you get familiar with your new telescope quickly.
Always remember never to look at or near the sun! Choose a land object that is easy to find and far away, such
as a mountain top. Roughly point the telescope at the object. Now look through the finder scope and move the
telescope until the red dot of light appears centered onto the object. If you are looking through an eyepiece with
low magnification, you should now be able to see the object in the telescope. Focus the image carefully, center it in
the field of view and fine tune the alignment of the finder if necessary.
Moon
The Moon can be observed best during the periods where less than 50% of its surface is bright. So you can see the
detailed shadows that the sun is causing when the light hits the craters from the side angle – creating a 3D-like
experience. We recommend using a neutral density filter for the Moon that reduces the glare. During a Full Moon,
the surface appears evenly bright without contrast and prominent structures. If you are spending a few successive
nights watching the Moon you will notice the change in the appearance of the mountains, craters and maria due to
the change of the phase of the Moon – a very interesting effect!
The planets
During their orbit around the sun the planets are continuously changing their position on the sky. When they are
visible, the following planets are especially suited for observations with your telescope:
Venus:
The diameter of Venus is about 9/10 the diameter of the Earth, and it is the third brightest object in the sky (after
the Sun and the Moon). As Venus orbits the Sun, you can observe the change of the light phases — sickle, half
Venus, full Venus — very much like the phases of the moon. The planetary disc of Venus appears white because the
sunlight is reflected by a compact layer of clouds that covers all surface details.
Mars:
The diameter of Mars is about half of the Earth’s diameter. In a telescope, Mars will appear as a tiny red-orange disk.
You may see a tiny white patch when you look at the polar regions that are covered in ice. About every two years,
when Mars and Earth reach their closest distance you can discover new features.
Jupiter:
The biggest planet in our solar system is Jupiter. In a telescope, the gas giant appears as a disk that is covered in
dark lines. Those lines are cloud bands in the atmosphere of Jupiter. Even with low magnification, 4 of the 67 moons
of Jupiter are often visible. These are the Galilean moons (Io, Ganymed, Europa and Callisto). Because those moons
are orbiting Jupiter the visible number and position changes. Sometimes a moon passes above the planetary disc
of Jupiter – then the shadow of the moon can be spotted on the planet as a sharp dark spot.
Saturn:
Saturn has a diameter about nine times the Earth’s diameter and appears as small roundish disc with a distinct
set of rings that bulge out from the edges of the planetary disc. Galileo, who was the first human observer of this
planet in 1610, couldn´t know that the planet had rings. Instead, he described Saturn as having “ears“. The rings of
Saturn mainly consist of billions of icy particles – ranging from tiny dust to the size of a house. The biggest division
in the rings, the so called “Cassini division” should be easily seen with your telescope in nights of steady air. Titan,
the biggest of the 62 moons of Saturn, is also visible as a bright, starlike object in the vicinity of the planet. Up to six
moons may be detected in your telescope.