Mon Sep 21, 2026 HG WELLS, GUSTAV HOLST
Herbert George Wells was born 160 years ago today. Besides “The Invisible Man,” and “The Time Machine,” he wrote “The War of the Worlds,” which was published at the end of the 19th century, at a time when there was a really big “Mars mania” sweeping the planet. The American astronomer Percival Lowell had recently announced his discovery of canals on Mars (Lowell was mistaken by the way; his telescope allowed him to see natural features on Mars like the Mariner Valley, but didn’t give him enough resolution to see them as anything but vague lines which he interpreted to be canals.) But at the time it was thought that life must exist on the red planet. Wells shares his birthday with the composer Gustav Holst, also born on September 21st in 1874.He was a musician, not an astronomer, but in 1915 he wrote a piece of music that you often hear in planetariums.It's called, "The Planets", and in it Holst wrote music to describe each of the seven known planets – except for earth!
Tue Sep 22, 2026 FIRST DAY OF AUTUMN
Today at 8:05 p.m. Eastern Daylight Time, fall will begin. This is the autumnal equinox, a point in time when, if you’re at the earth’s equator, the sun can be seen at the zenith, the top of the sky, at noon. Today, everyone around most of the world enjoys days and nights of pretty much equal length, hence the term “equinox,” which means “equal night”. From now until after the beginning of winter the sun will rise to the south of east and set to the south of west, and its noontime altitude will continue to decrease as well. The 23½ degree tilt of the earth’s axis causes the sun’s path across our sky to drift lower and lower at noon as we move toward winter. But folks who live below the equator are observing the beginning of spring: the seasons are reversed for earth’s southern hemisphere.
Wed Sep 23, 2026 NEPTUNE’S DISCOVERY
180 years ago this very night, on September 23rd, 1846, the planet Neptune was discovered. Johanne Galle used the Berlin Observatory’s nine-inch refracting telescope to search for a possible eighth planet in a small spot in the sky where the mathematician Urbain Leverrier had calculated it to be. Searching that spot, Galle saw a tiny, faint blue dot in the telescope’s eyepiece. Galle and his assistant Heinrich d’Arrest opened up their book of star maps, something called, the Berliner Akademischen Sternkarte, (I think I said that right,) and found that his star was “not on the map!” The next night they found that the tiny dot had moved against the background of fixed stars - it was a wanderer, a planet. Tonight, Neptune will be in the southeast after sunset in the constellation Pisces – but you’ll need a good telescope to find it!
Thu Sep 24, 2026 OLE ROEMER
Today’s Skywatch was written by my student assistant, Isabella Gargiulo. Danish astronomer Ole Romer was born on September 25th, 1644. Other than going on to become a royally appointed mathematician and astronomy professor, he was one of the first to grasp the speed at which light travels. By viewing about 140 eclipses of Jupiter’s moon Io, Romer discovered that the time between these eclipses shortened as our planet moved closer and took longer when Earth was farther away. From this observation, he deducted that light has a measurable speed. Many colleagues found this idea to be controversial, and it took almost two decades to finally be accepted in the scientific community. Throughout the rest of his life, Romer went on to invent Altazimuth mount telescopes, the modern thermometer, and the first streetlights in Copenhagen!
Fri Sep 25, 2026 FULL MOON OF SEPTEMBER
The moon is full tonight. It will rise out of the east at the end of the day. September’s full moon is the Barley Moon of medieval England, or the Singing Moon in Scotland and Ireland. The Chinese call this the Chrysanthemum Moon, while in the Americas it is the Corn Moon. The Cherokee call it the Black Butterfly Moon or the Nut Moon. Similarly it is the Little Chestnut Moon of the Creek and the Seminole people. It is the Drying Grass Moon of the Arapaho and the Cheyenne people, and the Choctaw Indian’s Courting Moon. The Comanche say it is the Paper Man Moon, but the Mohawk call this Moon the Time of Poverty. To the Omaha it is the Moon When the Deer Paw the Earth while the Sioux say it is the Moon When Calves Grow Hair. This is also the Harvest Moon, the full moon which occurs nearest the autumnal equinox, the beginning of fall, which was on September 22nd. The light of this full moon proved helpful to farmers who brought in their harvest of crops after sunset.
