More Saturn at Opposition

Saturn is at opposition today. That means the giant planet lines up opposite the Sun. Such an alignment provides the best viewing conditions for a planet. It rises at sunset and is in view all night. It’s closest to Earth at opposition as well, so it shines brightest for the entire year.

Tonight, Saturn will stand just a degree or two to the lower right of the Moon at nightfall. Coincidentally, the Moon is also at opposition, so it’s full.

Not every planet can go through opposition. Mercury and Venus orbit the Sun inside Earth’s orbit, so they can never appear opposite the Sun. As a result, you’ll almost never see either planet at true local midnight. Instead, they’re in view for only a few minutes or hours before sunrise or after sunset.

Saturn, Mars, and Jupiter, on the other hand, orbit outside Earth’s orbit, so they can circle all the way across the nighttime sky.

Saturn’s brightness can vary by quite a bit from one opposition to the next. That’s because we view its rings at different angles. Right now, the rings are at a fairly open angle, making Saturn especially bright. It’ll reach magnitude zero, making it brighter than all but the Moon and a handful of other planets and stars.

If you can’t see Saturn tonight, though, don’t worry. The planet will stay just about as bright for weeks after opposition — there’s not a sudden spike in its brilliance. So Saturn will remain a beautiful sight throughout the summer.

Script by Damond Benningfield