Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but with a telescope you can spot Neptune and Uranus.

Callisto, one of Jupiter’s largest moons, looks like a boring, crater-filled world. It doesn’t seem to have much going on ...

Mars, Venus, Jupiter, Saturn and Mercury will shine bright enough for the naked eye to see, and you can catch glimpses of Uranus and Neptune with binoculars or a telescope.

Just because a gas moon is possible, does not mean they will form easily. The key thing about gas planets is that they are ...