The surface of Mercury is crawling with snakes — more than two dozen of them. The largest is more than 165 miles long. You don’t need to worry about their bite, though — they’re remnants of ancient volcanoes.

The features are known as faculae — a Latin word that means “little torches.” They’re patches of bright material around dead volcanoes. The volcanoes erupted billions of years ago, when Mercury was young. They blasted out huge amounts of lava that contained a lot of water and similar compounds.

Planetary scientists have selected different themes for naming the surface features on Mercury and the other planets. Mercury’s faculae have been named for the words for “snake” in different languages. Some of the features look like snakes, and the god Mercury often was depicted with a snake on the end of his staff.

The largest snake is Nathair Facula, from the Irish word for snake. It’s about 165 miles in diameter. Other names include Inyoka, from the Zulu word for snake; Ular, from Malaysia; Abeeso, from Somalia; and Orm, from Sweden.

Not all faculae have been named yet. So we can look forward to more snakes wriggling across Mercury in the years ahead.

Mercury is in good view in the early morning now. It’s farthest from the Sun in our sky, so it’ll hang around for a few days. It’s in the southeast at first light, and looks like a bright star. But it’s so low that you need a clear horizon to spot it.

Script by Damond Benningfield

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