Saturn at Opposition

Every 12 and a half months, Earth moves past the giant planet Saturn. And that’s about the best time all year to watch it. It rises around sunset, is in view all night, and shines brightest for the whole year.

That alignment is known as opposition, and it’s coming up on Saturday. But there’s not much difference in the view for days before and after opposition, so don’t wait for that moment to look for Saturn.

It takes Saturn about 29 years to orbit the Sun, compared to one year for Earth. So we “lap” Saturn every 12 and a half months. If we could watch the two planets from above at high speed, the process would look like a small car on the inside lane of a race track zipping past a big car over and over. For every lap by the big guy, the little guy would make 29.

Saturn is at its closest around opposition — one reason it’s so bright. But its brightness varies from one opposition to another. That’s largely because we see Saturn’s rings at different angles. When the rings are most tilted as seen from Earth, Saturn shines roughly twice as bright as when the rings are seen edge-on. This year, they’re about half way between — adding to the luster of this plodding giant.

Look for Saturn low in the east-southeast at nightfall, and arcing across the south later on. It looks like a bright golden star. It’s well to the lower left of the Moon tonight, but the Moon will catch up to it over the next two nights.
 

Script by Damond Benningfield