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Jupiter

Big enough to hold every other planet inside it, and the best first target for a new telescope.

Seeing it from the UK

One of the brightest things in the night sky, a steady creamy white point that outshines every star. The remarkable part is how little you need to see more: ordinary binoculars, held steady or rested on a wall, will show the four big moons as tiny points in a line beside it, and they visibly move from one night to the next. That is the same view Galileo had in 1610 and it is still the best value five minutes in astronomy. A small telescope adds the cloud bands and, on a good night, the Great Red Spot.

Jupiter is more massive than every other planet in the solar system put together, twice over. Like Saturn it has no surface to land on. The bands you can see are cloud, and they run in alternating directions, which is why the edges between them are so ragged and full of swirls.

The Great Red Spot is a storm, and it has been going for at least a hundred and fifty years and possibly much longer. It is big enough to swallow the Earth, although it has been shrinking noticeably over the last century and nobody is entirely sure why.

It has at least ninety five moons, and four of them are worth knowing by name because you can see them yourself. Io is the most volcanically active place in the solar system. Europa has a salt water ocean under its ice, more water than all of Earth. Ganymede is the largest moon anywhere, bigger than Mercury. Callisto is one of the most cratered objects known.

The numbers

Distance from the Sun: About 484 million miles, five times further out than us
A day there: 9 hours 56 minutes, the fastest spin of any planet
A year there: 11.9 Earth years
Moons: At least 95, four of them visible in binoculars
The Great Red Spot: A storm wider than the Earth, running for centuries
Mass: More than twice everything else in the solar system combined, excluding the Sun

To find out whether it is up tonight, and when it gets properly dark where you are, see Sky Tonight.