The best kids' telescope to see planets

For planets specifically, a refractor has a real advantage that has nothing to do with aperture: there is no secondary mirror in the light path. A reflector's central obstruction scatters a little light and slightly softens fine contrast, which is precisely what planetary detail is made of.

At 102mm with a published 240x ceiling, this is the telescope here most likely to show Jupiter's cloud belts with structure in them and the Cassini division in Saturn's rings on a steady night.

The supplied 25mm and 10mm eyepieces give 26x and 66x. That is nowhere near the ceiling, and for planets it is the limiting factor rather than the optics. A single 6mm eyepiece takes you to 110x, and a 2x Barlow on the 10mm gives 132x. Budget for one of those.

Phone-guided finding is included, which for planets is less critical than for faint objects — Jupiter and Saturn are among the brightest things in the sky and easy to identify with a free app. It still saves time.

The all-rounder. 114mm gathers roughly 2.7 times the light of a 70mm, the mirror is parabolic rather than spherical, and Celestron publishes a 269x ceiling.

On planets that ceiling is theoretical rather than practical — the atmosphere rarely allows more than about 200x anywhere, and 150x is a good night in most gardens. But having headroom means the telescope is never the limiting factor.

The supplied 17mm and 10mm eyepieces give 26x and 45x. That is deliberately low, and it means the box as shipped is set up for star clusters and nebulae rather than planets. A 6mm eyepiece gives 75x and a Barlow on it gives 150x, which is where Jupiter starts showing belts.

12.8 limiting magnitude is the deepest published figure of anything we recommend. On the nights when planets are badly placed, that is what keeps the telescope worth carrying outside.

The cheapest way to see planets properly, and it is genuinely adequate rather than a compromise.

f/10 is a slow focal ratio, which suits planetary work: high contrast, forgiving focus, and cheap eyepieces perform well. The 2x Barlow on the supplied 10mm gives 140x, inside the published 165x ceiling. That is enough magnification for Saturn's rings to be obvious and for Jupiter's disc to show as a disc rather than a dot.

What 70mm reliably delivers on planets: Jupiter as a small bright disc with four moons in a line, changing night to night; Saturn with its rings clearly separated from the planet; Venus showing phases like a tiny Moon; Mars as an orange dot that occasionally hints at a darker marking.

What it does not: fine cloud structure, the Great Red Spot, or polar caps on Mars except at opposition on an exceptional night. Manage that expectation up front.

The value pick. 130mm of parabolic mirror gathers roughly 3.4 times a 70mm refractor, which shows up on planets as a brighter, higher-contrast image that stands up to more magnification.

At 650mm focal length, a 10mm eyepiece gives 65x and a 6mm gives 108x. The standard rule of thumb for maximum useful magnification — roughly twice the aperture in millimeters — puts a sensible ceiling near 260x. Sky-Watcher does not publish a figure of its own, so that is our arithmetic rather than their claim.

The trade-off against a refractor is real: the secondary mirror obstructs part of the aperture and slightly reduces contrast on fine planetary detail. In practice the extra light more than compensates for most of what a child will look at.

Collimation matters most on a fast reflector, and this is f/5. If the mirror drifts out of alignment, planetary views degrade noticeably before anything else does. Budget twenty minutes to learn it.