A maksutov cassegrain is the compact design that planetary observers reach for, and its reputation comes from one thing: at modest apertures it produces exceptionally sharp, high contrast images in a tube you can carry in one hand.
The corrector is the difference
Where a schmidt cassegrain uses a thin aspheric plate, a maksutov uses a thick spherical meniscus lens. Spherical surfaces are easier to make accurately, so a small maksutov can be figured to a very high standard cheaply. The penalty is weight: the corrector is thick glass, and it scales badly, which is why maksutovs above about 180mm are rare and expensive.
Why it suits planets
Long native focal ratios, typically f/12 to f/15, so ordinary eyepieces reach high magnification and cheap ones perform well. Combined with the sharpness of the optics, that makes a 127mm maksutov a common recommendation for lunar and planetary work, and a poor one for wide field deep sky, where the narrow field is limiting.
Cool down, which is the practical catch
A thick corrector and a sealed tube mean a maksutov takes longer than any other common design to reach ambient temperature, often an hour for a 127mm instrument brought out of a warm house. Observing before it has settled gives soft images that people mistake for poor optics.
Questions people ask about maksutov cassegrain
What is a maksutov cassegrain?
A catadioptric telescope using a thick meniscus corrector and two mirrors, compact, long focal ratio and known for sharp planetary images.
Is a maksutov good for beginners?
It is easy to use and needs no collimation in practice, but the narrow field makes finding objects harder without a computerised mount, and aperture per pound is poor compared with a dobsonian.
What is a catadioptric telescope?
Any design combining mirrors and lenses. The schmidt cassegrain and the maksutov cassegrain are the two common amateur examples.