What is the best telescope for viewing planets?

The nearer planets of our Solar System offer a feast for the naked eye on clear nights, but with a good quality telescope you can see much more.

Resolution is the name of the game with planetary observation and refractors are always a popular choice as their optical design offers higher resolution images than reflecting telescopes. Apochromatic optics are preferable as they cut down the colour fringing often associated with observing through lenses. However, even a budget refractor will improve your view and this optical design requires the least amount of maintenance. Astronomical telescopes usually show the image upside down – it’s brighter and, as any astronaut will tell you, there’s no up or down in space!

Newtonian reflectors are another popular type of telescope, usually offering a cheaper option to refractors as mirrors are not as costly to manufacture as lenses (and refractors can make use of multiple pieces of glass, adding to the cost). Whilst reflectors don’t offer the resolution of refractors, they come in larger sizes and their tubes are open so there is no need to wait for the telescope to adjust to the ambient temperature outside (something refractors must do before they can be used properly). Newtonian reflectors do, however, require a little more care when transporting as their mirrors can be knocked out of alignment. The image in a reflector is almost always upside down, due to the optical design (there are some eyepieces available that can correct this, but they are not hugely popular).

There is another optical design along with reflectors and refractors and that is the Cassegrain telescope. A reflecting telescope with a correcting lens, these are becoming ever more popular due to the high magnification they offer in a relatively short tube. The compact design has always been a strong selling point for these scopes and, like refractors, they can be adapted to show the image “right-side up”.

Of course, we can’t discuss telescopes without discussing the mounts that they come with. The most basic mount is an alt-azimuth type which gives you simple, easy movement in four directions. These are also quite often the cheapest option to consider and many beginners and first-time astronomers opt for these. For more accurate operation, equatorial mounts are preferred as they are designed to move within the equatorial plane of the Solar System, therefore giving much smoother tracking. The only thing to keep in mind is that these are not suited for terrestrial observation. And finally we have the GOTO mounts. These are computerised and track objects on their own. Always a popular option, they do require a power supply, but they make locating and tracking your targets an easy and user-friendly process.

There is also the Dobsonian mount. This is an alt-azimuth mount but, unusually, does not incorporate a tripod. Instead it has a large, circular base with two uprights to support the telescope tube. This type requires construction by the user, but they are the cheapest way to get a large-aperture scope on a user-friendly mount.

Smaller telescopes are perfectly fine for observing the nearer planets (Venus and Mars) and Jupiter as they are relatively bright and/or close to Earth. For the outer planets (Saturn, Uranus and Neptune) a larger telescope is needed because of the distances involved. Obviously the larger the scope, the higher the price, but it can be worth it to give you more potential targets. And, of course, for viewing objects beyond our Solar System (what astronomers refer to as “deep sky objects”) a larger aperture scope is essential – by larger we mean 5 inches and larger. 

We have a fantastic range of telescopes available on our website and in our store and we can cater for all budgets. Why not visit our Telescopes Available Now pages to see what we have in store!

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