Moon and Companions
A beautiful celestial triangle greets the new month at dawn tomorrow — the crescent Moon, the planet Mars, and the star Regulus. Regulus is close to the left of the Moon, with orangey Mars above them.
It’s early autumn in the northern hemisphere here on Earth, but it’s early spring in the northern hemisphere of Mars. As spring progresses, the planet is likely to see big dust storms. They form as carbon dioxide along the edges of the polar ice cap vaporizes and rushes into the atmosphere. That creates eddies and currents that stir up the Martian dust. The storms can cover thousands of square miles. And the biggest of all can cover just about the whole planet.
Mars’s orbit around the Sun is much more lopsided than Earth’s is. The planet is farthest from the Sun during the northern summer, and closest during northern winter. That means the northern hemisphere sees less extreme conditions during both seasons than the south does.
And since a Martian year lasts about 22-and-a-half Earth months, each season on the Red Planet averages about twice as long as its Earthly counterpart. Northern spring began at the end of July, and will continue until the summer solstice in February.
At the same time, Mars and Earth will be moving closer together, so the planet will grow bigger and brighter in the night sky, and rise a little earlier each night. It’ll put on its best showing of the year in April — the dead of summer in the Martian north.
Script by Damond Benningfield, Copyright 2013
For more skywatching tips, astronomy news, and much more, read StarDate magazine.