Five top targets in the Solar System

If you are the proud owner of a new telescope, you may be wondering what you can see through it. There is so much in the night sky that it can seem overwhelming. What to look at first! Here are five top targets in our Solar System for a small telescope. To check which objects are actually in the sky when you want to view, consult our Night Sky pages.

The dark lunar “seas” (Paul Sutherland)

1. The Moon. Before you go diving off into deeper space, don’t forget our planet’s partner in space! As well as being bright and easy to find, the Moon also offers lots to see plus an ever-changing face over the month as its phases wax and wane.

With the unaided eye alone, it is clear that the Moon is a discernible disk. But the only detail we can see like this is the darker patches that make up the waterless lunar “seas” or plains of lava. These are what produce the famous “face” of the Man in the Moon, for example.

Even a pair of binoculars will vastly improve the view, revealing the mountainous nature of the Moon’s surface and showing some of the larger craters caused by asteroid impacts. But the smallest of telescopes improves the view still further and offers countless features to study, including peaks, craters, valleys, rifts and mounds.

Not much happens on the Moon due to its lack of any significant atmosphere. But it ever-changing phase as it orbits the Earth means that the view is ever-altering too due to the different lighting and shadows as the angle of sunlight falling on the Moon changes.

You won’t normally see the Moon when it is at its New phase and therefore closest to the Sun, unless there happens to be a total eclipse in progress! Your first glimpse will come in the evening sky a couple of days later when it appears as a fine crescent after sunset. Over the next couple of weeks, watch as the phase gradually grows until, 14 days after New, we get Full Moon and the side facing us is totally illuminated by the Sun.

Oddly enough, when the Moon is Full, its appearance totally changes because virtually all those craters and mountains seem to disappear. The reason is that the Sun, on the opposite side of the sky, is shining directly down from our perspective and so all those shadows disappear. This also makes the Moon glaringly bright as the light is reflected directly back at us. Full Moon is a good time though to examine those lunar “seas” or maria. You will also see a couple of bright spots from younger impacts plus bright rays spreading away from them which are formed of the debris that was thrown out in those collisions. We have a beginners’ guide to help you find 50 fantastic features on the Moon!

2. Jupiter. The largest of the planets in our Solar System dominates the night sky when it is well-placed for viewing. Even the unaided eye shows it as far brighter than any star, shining steadily down but without any twinkling due to the fact it appears as a tiny disk rather than a starlike point, even though the disk is not visible without optical aid.

A pair of binoculars will immediately reveal that disk, plus you will see up to four points of light to either side of the planet, stretched out like a string of beads. These are Jupiter’s four largest moons, Io, Europa, Callisto and Ganymede, which Galileo discovered when he first used a telescope. With binoculars or a small telescope, you can see the positions of these natural satellites changing as they orbit the planet. You may not see all four when you look if one or two are in front or hiding behind Jupiter when you look.

A small telescope will show you that Jupiter is not spherical but appears rather squashed like a pumpkin at the poles, due to its gas-ball nature and rapid spin – it turns once in just under 10 hours. Look carefully through your telescope and you will begin to make out that Jupiter shows a pattern of light and dark bands or belts. These are more subtle to the eye than some sketches or photos suggest, but patience will help you see them. You may also see the famous Great Red Spot, a colossal storm that has been raging for centuries.

3. Saturn. The second largest of the gas giant planets is also further away and so appears smaller in your telescope than Jupiter does. However, what it lacks in size it makes up for with its splendid array of rings that encircle it. Formed from billions of particles of ice and rock, these create a spectacle unlike anything else in the heavens. Even binoculars will show the odd shape that the rings give to Saturn and a small telescope will provide a dazzling view. If the atmosphere is steady and gives you good “seeing” conditions, you may be able to pick out a dark gap in the rings called Cassini’s Division. Now and again, you may encounter a view of Saturn without its rings on display – this happens at the rare times when they appear edge-on to the Earth.

Saturn’s disk itself has a far blander appearance than Jupiter’s with a straw-yellow colour and none of the contrasting light and dark bands and belts. Occasional white spots, marking storms, appear which can be observed with larger amateur telescopes. Don’t expect any view like Hubble’s, but marvel at what we can see of this jewel in the sky.

4. Mars. Everyone is fascinated by the rocky red planet Mars. And when it is at its best, it makes a splendid target for your telescope. But because its distance from Earth varies greatly over just a few months, you have to pick your moments! Mars, the next planet out from our own, takes 687 days to orbit the Sun, which means we overtake it on the inside every 780 days or so. For a few weeks or months around that time, it is close enough to show a small orange disk in a backyard telescope, and you might be able to pick out a few dark features or the white polar ice caps. But a year or so later, when Earth and Mars are on different sides of the Sun, it will appear much fainter in the sky and you won’t see anything on its dot of a disk at all. Mars’s next closest approach, called Opposition, occurs in March 2012 so it is getting to be a good time to observe it as I write this! Skymania offers a special guide to Mars including a sky map to help you find it.

5. Venus. Our other neighbour planet, only slightly smaller than Earth, lies closer to the Sun. This means it can never be seen to shine in the middle of the night because it either follows the Sun down after sunset or rises ahead of it before dawn. Because, like all the planets, Venus shines due to reflected sunlight, it shows phases just like the Moon does. When it is on the far side of the Sun, it appears as a tiny disk, but when closer to us its appearance varies between that of a “half moon” and a wider crescent. Venus shines brilliantly and is the brightest object in the night sky after the Sun and Moon. It can even be seem with the unaided eye in broad daylight if you have a clear blue sky and know just where to look. Its phases are easy to see in a small telescope and may be made out in binoculars, although be very careful never to sweep the sky for it while there is a danger you might accidentally point at the blinding Sun. Despite its brightness, due to sunlight reflecting from Venus’s permanent veil of cloud, you won’t see any significant detail in those clouds with a small telescope, though some claim to see subtle shadings.

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