Saturn is at its brightest this weekend. The reason is a neat piece of sky geometry called opposition, and it happens for every outer planet.

Opposition means Earth sits directly between the Sun and the planet. The planet is then at its closest to us, fully lit by the Sun, and visible all night, rising at sunset and setting at sunrise.

For Saturn, opposition falls on October 4 this year. This is the best night to see it: brighter than usual and up the whole night. Through a telescope, its rings are the star of the show, currently tilted nearly edge-on in a rare alignment.

You can watch opposition nights without any equipment too. The planet looks like a steady, golden star that does not twinkle much. Just look east after sunset and enjoy the closest view of the ringed giant until next year. Jupiter and Mars get their own opposition nights too, each with the same geometry at work.