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Mars and Antares

August 23, 2016

Mars passes its legendary “rival” the next few evenings — the star Antares, at the heart of Scorpius, the scorpion. The two are in the southwestern quadrant of the sky, with the planet Saturn looking down on them.

Antares gets its name because it resembles Mars. Both bodies look reddish orange, and both are bright. Antares also lies along the path the Sun and planets follow across the sky, so every couple of years, Mars passes quite close to it.

When they put that all together, skywatchers thought of Mars and the star as rivals, so the name Antares means “rival of Ares,” the Greek version of Mars.

Of course, any rivalry between a planet and star is one-sided. Mars is a ball of rock and metal a bit more than half the diameter of Earth. It looks red or orange because its surface is coated with orange dirt.

Antares, on the other hand, is a supergiant, which makes it one of the biggest stars in our region of the galaxy. If Antares replaced the Sun in our own solar system, it would extend beyond the orbit of Mars — putting a quick end to its famous rival.

Look for these two rivals in the southwest as night falls. Mars is the brighter of the two, shining like a brilliant orange star. Antares is close to its lower left this evening, but almost directly below Mars by tomorrow evening. After that, Mars will slide slowly eastward, leaving Antares behind. The golden planet Saturn, which is fainter than Mars, stands just above them.


Script by Damond Benningfield

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