September stargazing: A blood moon, Venus vs Jupiter (Round Two), and a new season

If you’re not in North America, this month’s full moon will make for pretty compelling viewing: the full moon coincides with another full lunar eclipse! Why yes, that means it is also a big ol’ blood moon! But even if your eyes are shielded from that particular piece of cosmic horror, September has a couple of other celestial tidbits to offer persistent stargazers.

September 7: Full, Potentially Bloody, Corn Moon

September’s full moon is the Corn Moon, a quintessentially American name if there ever was one. But as it happens, the full moon also coincides with the second full lunar eclipse of 2025—which means that it’s also a blood moon due to its signature rosy hue! This leaves us with… a bloody corn moon? A corny blood moon? An ‘80s slasher moon? Whatever you want to call it, some 6.1 billion people in Asia and the western part of Australia are about to see a decidedly sanguine full moon.

Unfortunately, those of us in North America aren’t among them. Unlike March’s lunar eclipse , the moon will be below the horizon by the time it is plunged into shadow. We’ll just be left with the corn. Always with the corn. 

If you’re wondering exactly why a lunar eclipse turns the moon red, instead of hiding it completely, the short answer is that the earth’s atmosphere refracts light onto the moon’s surface. Long-wavelength red light gets refracted the most, so this rosy light hits the moon. The long answer awaits you here. And if you want to see the full moon in all its unstained glory, the indispensable Farmer’s Almanac informs us that our satellite will reach peak illumination at 2:09 p.m. ET on September 7.

September 16: Venus Returns For Another Dose of Jupiter

Venus and Jupiter have been spending a lot of time together of late. Last month found them hanging out in the same part of the sky.The Goddess of Love clearly liked what she saw, because they’ll be spotted together again this month. 

The two planets will appear near each other low in the east-northest of the sky, with Jupiter rising first, between 1:30 a.m. and 3 a.m., and Venus following between 4:30 a.m. and 5:45 a.m. Chicago’s Adler Planetarium suggests that the best time to see just what they’re getting up to will be September 16, when they’ll have  a delicate crescent moon for company. 

September 22: Autumnal Equinox

You’re probably familiar with the summer solstice (the longest day of the year) and the winter equivalent (the shortest day). But there are also equinoxes that mark spring and autumn. On these days, night and day are of roughly the same length,hence the name “equinox.”, a sort of Latin portmanteau of the words for “equal” and “night”. The Northern Hemisphere’s autumnal equinox is the spring equinox in the Southern Hemisphere (or “vernal equinox,” to give it its proper name), and vice versa.

One such event is happening on September 22 at 2:19 p.m. ET. In the Northern Hemisphere, it’s the autumnal equinox. The event marks the start of fall from an astrological point of view. From here, the days will get progressively shorter until the winter solstice (but more darkness means more time for stargazing!). Officially, meteorological fall begins on September 1 every year, but where’s the fun in that?

Anyway, whenever you find yourself staring skywards in September, remember that you’ll get the best experience if you get away from any sources of light pollution—and you check out our stargazing tips before you head off into the night.

Until next month!

 

More deals, reviews, and buying guides

The PopSci team has tested hundreds of products and spent thousands of hours trying to find the best gear and gadgets you can buy.