Top astronomy events for September 2025
From a total lunar eclipse to Saturn shining bright all night long, here are the top astronomy events to mark down on your September calendar.
Saturn is about to make its closest approach to Earth, and that means you might be able to see its rings — if you have a telescope, that is.
Here’s what to look for this weekend.
When will Saturn be closest to Earth?
On Sunday, Sept. 21, one day before the official start of fall, Saturn will be at what’s called “opposition,” which in astronomical terms means the ringed planet will form a temporary line — the sun on one side and the Earth passing between them. Thanks to sunlight illuminating Saturn’s surface, it will appear exceptionally bright.
How close will Saturn get to Earth?
Earth’s outer planets are at their closest for the year during opposition, according to EarthSky. Saturn will be approximately 795 million miles (1.28 billion kilometers) away from Earth.
How big is Saturn compared to Earth?
Saturn is roughly nine times wider than Earth, writes NASA, with a diameter of about 74,897 miles. That means if Earth were the size of a nickel, Saturn would be as a big as a volleyball.
Where to spot Saturn in September 2025
Even if the weather doesn’t cooperate, Saturn should be visible all night in late September, writes EarthSky.
Saturn will rise in the east close to sunset. Look for the ringed planet in the constellation Pisces.
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How to stargaze
Experts recommend you do the following to get the most out of the experience:
Get out of the city. Find a dark location far away from light pollution.Give your eyes 20-30 minutes to adjust to the darkAvoid looking at phones or bright lights. Face away from the moon if you can.Dress comfortably for the weather.Bring a bottle of bug spray, a blanket or a comfortable beach chair, then sit back and enjoy the show.
CONTRIBUTING: Jenny Porter Tilley.