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The Landing Help

By — McGraw-Hill Professional
Updated on Sep 16, 2011

The Landing

The Mars lander, the Eagle , awaits. You’re not eager to get inside its cramped cabin and endure weightlessness, even for a short while. The artificial-gravity wheel on the Valiant has been slowing down gradually since you left Venus, where the gravitational pull is nearly equal to that of Earth. The shock of weightlessness nevertheless will be unpleasant; you have never tolerated it well.

Finding A Spot

Your first question, naturally enough, is “Where will we land?”

The first officer responds, “The best places, in my experience, are the calderas (craters) of old Martian volcanoes. While some of the volcanoes on Mars might still erupt from time to time, none are active at the moment. If a volcanic eruption were imminent, there would be signs, just as there are on Earth.”

“What kinds of signs?” you wonder.

“We have seismometers in all the landing-site calderas,” says the first officer. “The one we will be visiting today is called Pavonis Mons . This means “Peacock Mountain.” It lies almost exactly on the Martian equator. It happens to be only a few days past the Martian vernal equinox, so the Sun will rise directly in the east, follow a course right up to the zenith, and then set in the west, 12 Mars hours later.”

“A Mars hour is . . .”

“About 62 Earth minutes,” says the first officer. “We have decided to divide the Mars day up into 24 hours according to the Sun, just as is done on Earth. You won’t notice any difference between Mars time and Earth time. We have special wristwatches with quartz oscillators aligned so that they function according to Mars time. Here.” He hands you a watch. You strap it on over your pressure suit.

The descent proceeds smoothly enough. A huge crater yawns beneath the Eagle . “I don’t like this,” you say. You have visions of an impromptu Vesuvius or Krakatoa eruption replay, with the Eagle as part of the volcano’s ejecta. “No need to worry,” says the first officer. “If there is any sign of trouble, which is less likely than getting hit by a bolt of lightning on Earth, we’ll be out of here. We have rehearsed all kinds of emergency evacuation scenarios.”

It is almost sunset as the Eagle touches down. At the last moment before touchdown, the Sun vanishes beneath the rim of the crater. The sky above is pink where the Sun was, magenta all around, fading to deep purple and finally to black at the zenith. You think that you see a tiny white dot moving down toward the eastern horizon. “Is that Phobos?” you ask.

“No,” the first officer says, “That is our main ship.”

The Martian Night

The outside temperature is –40°C, which happens also to be –40°F, at sunset. The thermometer plummets fast. It will drop down to –90°C, or –130°F, in the predawn hours.

“That’s colder than it ever gets in Antarctica,” you say.

“And the thin air, if you could stand outside and not die from the lack of pressure, would make it seem even colder than that.”

“I can’t imagine –130°F, no matter what the pressure,” you say.

“Think of the worst possible arctic blizzard, with the temperature far below zero and the wind roaring like a hurricane. Then imagine getting into a swim suit and going outside and just standing there.”

“I get the idea.”

“At the poles during the Martian winter, it can get quite a lot colder even than that,” says the first officer.

“It is beyond my comprehension.”

“Now we need to get some sleep,” says the first officer.

“In this cramped little vessel?” you ask.

“Well, not out there on the Martian desert sand. If you want to stay awake all night, go ahead, but don’t keep me up.” He nods his head and begins to doze off. All you can do is peer out the window and try to see if you recognize any constellations. You think you see Orion, tilted nearly on its side, hovering low in the eastern sky.

Then you, too, fall asleep. You wake up to sunshine on your face after what seemed like only a few seconds.

“The dreamless sleep of space explorers,” says the first officer. “And now we will perform the little test for which we came.”

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