Moon and Companions

The Moon looks down on a couple of ancient “rivals” before and during dawn tomorrow — the planet Mars and the star Antares. They’re quite low in the southeast at first light. Mars is close to the lower left of the Moon, with Antares about the same distance to the lower right.

Mars is one of the reddest objects in the night sky, which has always drawn attention. Long ago, that color reminded skywatchers around the Mediterranean of blood, so they named the planet for the god of war.

In Rome, the god was called Mars. But in Greece, he was Ares. And that’s where the star Antares got its name. The star is bright and orange, like Mars, so it was named “Ant-Ares” — the rival of Ares.

The comparison was easy to make because Mars passes by the star every couple of years or so. When they’re close together, they really can look a lot alike — but not always. Antares always looks the same — it doesn’t change. But as Mars orbits the Sun, it gets a lot brighter or fainter depending on its distance from Earth. At times, it’s a good bit fainter than Antares. At others, it’s many times brighter.

Mars is just emerging from behind the Sun now, so it’s a long way away, which makes it fainter than Antares. But by next December, Mars will line up opposite the Sun, so it’ll be closest to us for the year. It will shine about 20 times brighter than it is now — truly outshining its colorful rival.

Tomorrow: seeing in the new year with the stars.

Script by Damond Benningfield