Planet

Jupiter

The largest planet. Its four brightest moons and its cloud belts are within reach of every telescope.

When to look: The months around its opposition, when it is visible most of the night. The date moves later by about a month each year.

What it looks like

Described as seen by eye at the eyepiece, on a clear night. Photographs collect light for minutes or hours and show far more colour and detail.

With the naked eye: A very bright, steady point of light - often the brightest 'star' in the night sky after Venus.
Small telescope (60-90 mm): A small disc crossed by two dark cloud belts, and the four Galilean moons - Io, Europa, Ganymede and Callisto - as points of light that change position from night to night.
Medium telescope (114-150 mm): More belts and zones, the Great Red Spot when it faces Earth, and the black shadows of the moons when they cross the disc.
Large telescope (200 mm and up): Festoons, knots and fine structure in the belts on nights of steady air.

City or dark sky

From a city

Planets are bright enough that city lights barely matter. Steady air matters far more.

From a dark site

Little difference for Jupiter; steady air is what counts.

Observing tip: Let the telescope cool outdoors for about 30 minutes and observe when Jupiter is high in the sky. The disc looks small: detail appears in moments of steady air, so keep watching rather than expecting a photograph.