Finding it? A no-brainer. Just step out anytime after 8:30 p.m. Look around. The night has two stars brighter than any others. One is blue-white: This is the Dog Star, Sirius, floating lower left of Orion's belt. The other is orange: That's Mars.
Of course the constellations shift during the night. So here's an unnecessarily specific guide, tailored to the time you choose to look up. At 8 p.m. Mars is lowish in the east, while Sirius stands at the same height, a long way to Mars's right. After 9:30 p.m., Mars stands much higher up than Sirius. Then at 1:30 a.m., the two are vertical, with Mars directly above but still distant from the much-lower Dog Star. In short, between 8 p.m. and 1:30 a.m. the pair shift from horizontally aligned to vertically.
The two create a fabulously lovely color contrast, and they're an almost-perfect match for brightness. But this is odd: Usually when Mars comes to "opposition" - meaning opposite the Sun and closest to Earth - it vastly outshines Sirius. It even outshone Jupiter during the historic Martian close approach seven years ago. Its current "best" reveals that this is really not a very close visit.
Mars's orbit is oval, lopsided. Every 26 months, when Earth and Mars meet, the encounter can occur at either a narrow gap between our orbits, as it did in August 2003, or the widest-possible gap, which will happen next time, in March 2012. This time it's nearly at its worst, which makes it appear very small through backyard telescopes - although the view through SLOOH, the amazing online observatory, has been fairly impressive. It is now late spring on Mars, and the northern polar cap is melting. But right now it's still prominent. Use SLOOH.com to have a live look at it any night.
Mars has always held the fascination of humans - even in ancient times, when it was thought to be a god circling the Earth. For what non-divine object could behave so mysteriously? What could be the reason for its corkscrew motions, tremendous changes in brightness and reddish color?
Despite all that, most of the time Mars wouldn't catch anyone's attention, shining as a medium-bright "star" ten times less brilliant than it is this week. But it all changes when Earth overtakes slower Mars and glides past it for a few weeks. Then Mars seems to reverse its direction: the famous retrograde motion, whose explanation is as simple as why a car in the slow lane seems to go backward when you pass it on the highway.
Mars will remain an impressively brilliant "star" only for the next few weeks. It will lose half its light during February, so don't wait to look for it.
Owners of small telescopes should choose a night when the air is steady - a relatively rare state of affairs characterized by non-twinkling stars. Then, surface details and its polar cap can be glimpsed. Still, observers are often dismayed by the small size of Mars' disc: only 14 arc-seconds, or just one-third the apparent size of Jupiter.
If you haven't a telescope, fine. Then you're left with the simple assignment of locating the brightest orange star in the heavens. If you have binoculars, sweep them to the right of Mars, to enjoy the famous star cluster in Cancer known as the Beehive.
Oh, and on Friday the 29th, watch the Full Moon hover next to Mars. This is the closest and largest Moon of 2010, and will offer quite a gorgeous sight as the pair rise at sunset.
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