StarDate

The planet Venus and the star Spica huddle close the next few evenings. They’re quite low in the west-southwest in early twilight. Venus is the brilliant “evening star.” Tonight, Spica stands close above it. Venus will slide to the left of Spica over the following nights.

Venus is named for the Roman goddess of love and beauty. It’s the only major planet in the solar system named for a female character. With a few exceptions, all of the features on its surface are named for women as well – from both mythology and real life.

No features were named until the Space Age. Venus is covered by an unbroken blanket of clouds, so we can’t see the surface. Radio telescopes on Earth peered through the clouds in the ’60s, and discovered the first known features. All the other features were mapped by spacecraft in orbit around Venus, which scanned the planet with radar.

Today, more than 2,000 features have been named – mountains, craters, canyons, plains, and others. Their names have come from cultures around the world and across the ages.

One volcano is named Anuket, for an Egyptian river goddess, while another is named La Shen for a Chinese goddess. Other features are named for Anne Frank, Jane Austen, Pocahontas, and Queen Isabella of Spain, along with other writers, artists, rulers, scientists, and women from many other fields – all commemorated on the planet Venus.

Script by Damond Benningfield

If you look carefully at pictures of Saturn, you’ll probably notice something odd about the planet – it looks mashed down, like a beachball that a child is sitting on. The planet is more than 7,000 miles wider through the equator than the poles – only a bit less than the total diameter of Earth. That makes it the “flattest” planet in the solar system.

Saturn is the Sun’s second-largest planet, after Jupiter – more than nine times the size of Earth. But it’s much less dense than any other planet. It’s a big ball of hydrogen and helium – the two lightest elements – wrapped around a messy core of rock and metal.

Despite its size, Saturn spins in a hurry – its day is less than half as long as a day on Earth. That high-speed rotation pushes material outward at the equator – giving Saturn that “squashed” appearance.

That shape affects the planet’s gravity. Saturn’s poles are much closer to the center of the planet than the equator is. And anything at the equator is being pushed outward by the high-speed rotation. The combination means that you’d weigh about a third more at the poles than at the equator – perhaps making you feel more squashed on this giant but squashed planet.

Look for Saturn close to the lower right of the Moon as they climb into good view, in mid-evening. It looks like a bright golden star.

Tomorrow: famous women on the planet Venus.

Script by Damond Benningfield

The world’s top tennis players will spend many hours under the lights over the next two weeks. And thanks to some changes made a couple of years ago, almost all of the light will shine down on them – not into the sky.

The U.S. Open is played on 17 tournament courts and five practice courts in Queens, New York. Many of the sessions take place at night. But conventional outdoor lighting directs a lot of light into the sky, producing light pollution. To reduce the glow, the venue replaced its lighting in 2024. The new L-E-D fixtures are shaped and shielded so that almost all of their light shines down onto the courts.

The change was certified as “dark-sky friendly” by DarkSky International, a group that’s been encouraging better outdoor lightning for 25 years. Cities, parks, and other places get certified by changing their lighting, and enacting policies designed to keep night skies dark.

In all, the group has certified more than 270 sites around the world. And since 2019, it’s certified more than 40 sports venues, most of them in the U.S. – from Texarkana to Waukesha, Wisconsin, and from Seattle to Panama City, Florida.

Light pollution does more than just ruin the view of the night sky. It can interfere with the migration of birds, sea turtles, and other animals. It wastes energy and money. And it can hurt people’s health. So reducing light pollution is a winning strategy.

Script by Damond Benningfield

The Moon will ply the dark waters of the celestial sea the next few nights – a large region of sky that’s populated by constellations related to water. Tonight, the Moon sails from Aquarius the water bearer into Pisces, the fishes. Pisces is so long that the Moon will remain inside its borders until Monday night.

The “sea” consists of six major constellations. Together, they cover almost one-eighth of the entire sky.

All of them were created thousands of years ago by cultures around the Mediterranean Sea. The constellations probably were associated with water because the Sun passed across them during the rainy season.

Like the open ocean on a moonless night, the entire region is dark – most of its stars are quite faint. The brightest of the lot is Fomalhaut. It’s in Piscis Austrinus, the southern fish. The star climbs into view in the southeast in early evening, and swims across the south during the night. It’s bright on its own, but the lack of other bright lights around it makes it really stand out.

Pisces is especially dark. Most of its stars are impossible to see from light-polluted cities, or even the suburbs. And with the almost-full Moon passing through, it’s hard to see any of its stars even from sites that are far away from city lights. So as the Moon moves across the constellation, it looks like it’s floating through an ocean of darkness – the cosmic waters of the celestial sea.

Script by Damond Benningfield

A season comes to an end today. It has nothing to do with falling leaves, changing weather, or even big-time sports. Instead, it’s a season of eclipses. It didn’t last long – it started on August 12th, with a total solar eclipse, and it ends tonight, with a partial lunar eclipse. The Moon will be almost completely immersed in Earth’s long shadow, so it’ll turn dark. And at least part of the eclipse will be visible across almost all of North America.

An eclipse season is governed by the way in which the Sun and Moon align. Most months, the geometry isn’t right – the Moon and Sun don’t line up the right way, so there are no eclipses at all.

But every 173 days, they come into the proper alignment. That produces a solar eclipse at new Moon, and a lunar eclipse at full Moon. They can come in either order, a fortnight apart. And a season lasts for about five weeks – a few days longer than the Moon’s cycle of phases. So if there’s an eclipse near the start of the season, it produces three eclipses. This time, the solar eclipse came a few days after the season began, so we’re limited to two eclipses – including tonight’s.

The Moon first dips into Earth’s dark inner shadow at 9:34 p.m. Central Time. The eclipse peaks at 11:13, when the shadow covers 96 percent of the lunar disk. It ends an hour and a half later.

Script by Damond Benningfield