The Sea

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Fall usually isn't the best time for an outdoor swim -- unless you're swimming through the night sky. A half-dozen "watery" constellations spread across the firmament, forming a region known as the celestial sea. By midnight, they span the entire southern sky.

From west to east, the lineup includes Capricornus, the sea-goat; Aquarius, the water bearer; Piscis Austrinus, the southern fish; Pisces, the fishes; Cetus, the whale or sea monster, and Eridanus, the river.

Much of the association with the water comes from the time of year the constellations put on their best showing: autumn, which was a rainy season for much of the Mediterranean, where the constellations were named.

There aren't a whole lot of standout stars in the sea. The brightest is Fomalhaut, in the southern fish. It stands low in the southeast at nightfall. It's easy to spot because it's the only truly bright star in that whole region of the sky. We'll have more about Fomalhaut tomorrow.

The standout constellation is probably Capricornus, because it forms the most easily seen shape -- a wide triangle that's often compared to the bottom of a bikini bathing suit. But most of its stars are fairly faint, so you need to get away from city lights to see the sea-goat.

Capricornus is in the south at nightfall, and wheels across the southwest later on. The other stars of the sea follow it. Eridanus is the last to rise, with its meandering trail of stars clearing the southeastern horizon by around midnight.

Script by Damond Benningfield, Copyright 2008

For more skywatching tips, astronomy news, and much more, read StarDate magazine.