After a summer that featured Mars at its brightest, the century's longest "blood moon" eclipse, and a brilliant display from the Perseid meteor shower, what could September possibly offer for an encore? Dust off that sweatshirt, grab a blanket, and enjoy the waning weeks of summer while you're looking up into the evening sky. Below are just some of the highlights to look for.
Neptune is ready for its close-up (Sept. 6)
Neptune, home to the solar system's fastest wind speeds (1,600 mph), will make its closest approach (perigee) to Earth on Sept. 6. The blue hydrogen and helium giant will be visible in the constellation Aquarius for most of the night. Despite its "close" approach of 2.7 billion miles, the planet will appear as little more than a pale, blue dot. Those with backyard telescopes can get a better view by training their gear on the southeastern sky after midnight local time.
Sneak a peek at the Epsilon Perseids (Sept. 9)
The Epsilon Perseids aren't known for being particularly exciting, but there's always a chance of a surprise fireball or two. (Photo: Dhilung Kirat/Flickr)
Ever hear of the September Perseids? Also known as the Epsilon Perseids, this relatively unknown meteor shower peaks on Sept. 9. They are relative obscure because displays are generally less than impressive, with perhaps no more than five shooting stars per hour. That said, astronomers were caught off-guard in both 2008 and 2013 when outbursts of meteors from the Epsilons graced the skies.
To take a shot at spotting your own rare September fireball, look north towards the constellation Perseus after dark.
Dark skies welcome the New Moon (Sept. 9)
The New Moon's arrival on Sept. 9 will give astronomers in dark sky sites an unimpeded view of the heavens. (Photo: Wenjie Qiao/Flickr)
Giving star gazers one more shot to enjoy relatively warm evenings, the New Moon of September will stealthily glide across the evening sky and give way to the glow of the heavens. Now is the perfect time to catch dim constellations and other celestial highlights often washed out by the more luminous phases of the moon.
Wave hello to a passing green comet (Sept. 10)
Comet 21P/Giacobini-Zinner as captured on Aug. 18, 2018 from Moscow. (Photo: Alexander Vasenin/Wikimedia Commons)
On Sept. 10, Comet 21P/Giacobini-Zinner (or 21P for short), will make its closest approach to Earth in 72 years. The 1.24 mile-wide comet is notable for its distinctive bluish-green glow that increases in brightness as it passes closer to the sun. The debris it sheds as it warms is also responsible for the annual Draconids meteor shower, which peaks in early October.
Despite it's close approach, 21P will only get within 36 million miles of Earth. By comparison, Mars in late July came within 35.8 million miles. To see it, grab a pair of binoculars and look for the bright star Capella just above the northwest horizon at midnight. 21P should appear as a fuzzy green spot. Thanks to a waning New Moon, the dark night sky should provide decent viewing conditions.
Slip into fall (Sept. 22)
The fall equinox occurs in the Northern Hemisphere on Sept. 22. (Photo: Jamie McCaffrey/Flickr)
On Sept. 22 at 9:54 p.m. EST, we'll say goodbye to the lazy days of summer and welcome the start of fall with the autumnal equinox. According to Time and Date this event marks "the moment the sun crosses the celestial equator – the imaginary line in the sky above the Earth’s equator – from north to south and vice versa in March." It's also a time to start thinking about firewood, carving pumpkins, warmer clothing, and an anticipation of the colder months that lie ahead. According to the Farmers' Almanac, some parts of the U.S. could be in for quite a winter.
Behold the Full Corn Moon (Sept. 24)
The Full Corn Moon is September's full moon. (Photo: Patrick Emerson/Flickr)
September's full moon, nicknamed the Corn Moon, will rise on Sept. 24 at 10:53 p.m. EST. The moon earned its moniker from Native Americans who would begin harvesting corn in September. For similar reasons, it's also known as the Barley Moon. Other nicknames include the Moon When the Plums Are Scarlet by the Lakota Sioux Native Americans and the Moon When the Deer Paw the Earth by the Omaha Native Americans.
Editor's note: This story has been updated since it was originally published in August 2017.