How much aperture does it take?

Seeing Jupiter through a telescope

A small bright disc with two dark stripes across it, and four points of light in a line either side. The moons move visibly from hour to hour.

Through three telescopes, under a suburban sky

Each circle is the true field of a 10 mm eyepiece. Same target, same sky; only the aperture changes.

70 mm · 49×

Recognisable

130 mm · 91×

Detailed

250 mm · 175×

Detailed

Jupiter does not care about light pollution: it is bright, and the air, not the sky glow, sets the limit.

Level	Milky Way blazing	Milky Way, barely	No Milky Way
Detectable	10 mm	10 mm	10 mm
Recognisable	50 mm	50 mm	50 mm
Detailed	100 mm	100 mm	100 mm

The Great Red Spot needs about 100 mm and a steady night; it is salmon-pink rather than red, and it is only facing you for a few hours at a time.

Best when it is highest around midnight — check for the current year.