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Venus and Antares

January 22, 2011

Two of the brightest objects in the night sky slip past each other the next few days. One of them is a planet, while the other is a supergiant star. But just which one is which can be a bit of a surprise.

Venus and Antares are well up in the eastern sky at first light. Venus is the brilliant "morning star," with Antares to its right or lower right.

Venus is by far the brighter of the two, so you might expect it to be the more impressive of the two as well. That's not the case, though -- not by a long shot.

Venus is one of the planets of our solar system. It's about the same size as Earth, which is quite small on the astronomical scale. It shines so bright because it's close to Earth, and because it's close to the Sun, so it reflects a lot of light into space.

Antares, on the other hand, is one of the biggest stars in the galaxy -- a supergiant that spans about three times the distance from Earth to the Sun. If it took the Sun's place in our solar system, it would engulf all four of the inner planets, including Venus and Earth. That makes Antares big enough to hold 400 million million Venuses.

Look for these two bright but deceptive objects climbing the eastern sky beginning about three hours before sunrise, and in good view in early twilight. Venus will slide past Antares over the next few mornings, but they'll remain fairly close together for a few weeks.

We'll talk about two more bright morning objects tomorrow.

Script by Damond Benningfield, Copyright 2010


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