Stargazers | Seeing the Red Planet
It was Halloween eve, 1938. Millions of war-jittery Americans listened as special news bulletins reported that the tiny town of Grover's Mill, N.J., had been captured by invaders from Mars.
It was only a radio play, a re-creation of H.G. Wells' novel "The War of the Worlds," cleverly disguised as a newscast by the radio magic of Orson Welles.
Those who didn't know, however, were panic-stricken. Police and military switchboards lit up. And the quiet of that October Sunday evening was shattered by a horrible, yet totally imaginary, invasion from Mars.
If you've ever seen Mars at its best, you can certainly understand how the Red Planet has inspired the human imagination since people first began looking skyward ages ago. And now, nearly 78 years after that famous broadcast, is a great time to see Mars at its best.
Mars now appears against the stars of the constellation Scorpius, which, of course, lie trillions of miles farther than the planet.
It reaches opposition on May 22, when the planet lies directly opposite the sun in our sky. Head outdoors shortly after dark around that date, and stand with your back to the sunset point. There, in front of you, will glow the brilliant orange light of Mars. It will be hard to miss because it outshines everything else in that area of the sky.
Stargazers who keep a close eye on the Red Planet over the next few weeks will notice it drifting from the top of Scorpius westward into the constellation of Libra. By the end of June, however, Mars will stop its westward motion against the stars and begin heading eastward once again. By early August, it will again pass the stars of Scorpius, but will appear five times fainter.
To understand why this happens, imagine viewing Earth, Mars and the sun from space. Each day, our planet moves 1.5 million miles along its orbit around the sun. Mars, orbiting farther from the sun's gravitational pull, travels more slowly. This means that every 26 months or so, the Earth catches up with Mars from behind, passes it on the inside, and then gradually pulls ahead of it.
You can think of it as two race cars on concentric circular tracks. If the inner car is traveling faster, it will regularly lap the outer car, and the driver will see the outer car appearing to move backward for a short time.
Mars will actually reach its closest point to Earth, only 46.7 million miles away, on May 30.
If you own a small telescope — or if you can visit your local planetarium or amateur astronomy club to access to a telescope — you'll get an even more remarkable view of this alien world. Unless a Mars-wide dust storm kicks up, its dark surface features should appear among its red Martian sands, and you may even glimpse one of its white polar ice caps glistening in the sunlight. So don't miss this chance!
Additionally, on May 22, the ringed planet Saturn will appear between the moon and Mars. Saturn is now approaching its own opposition, but that's a story for next week.
Visit Dennis Mammana at www.dennismammana.com.
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