The first lander, Spirit, is scheduled to land tonight at 8:30 PST. I hope it makes it there safely.
FINAL FRONTIER DEPT.
THE SUN ON MARS
Issue of 2004-01-05
Five years ago, at a meeting of Cornell University scientists to discuss the design of Mars probes for nasa, there was spirited debate, naturally, on the question of photometric calibration. What sort of apparatus would enable an unmanned spacecraft’s cameras to adjust their color values to Mars’ atmosphere? (The digital images radioed home by the Viking lander in 1976 were notoriously “over-pinked”; if you actually stood on Mars, you would see a landscape whose color resembled not cotton candy but butterscotch.) The consensus favored a post that would cast shadows across a “calibration target” of gray rings—and then Bill Nye piped up. Nye is a Cornell alumnus and a mechanical engineer whose hydraulic-pressure-resonance suppressor is used on the Boeing 747. But he is best known as the excitable, bow-tie-wearing, bubbling-beaker-holding host of the PBS show “Bill Nye the Science Guy,” and he spoke now in his most irrepressible manner: “C’mon guys, it’s got to be a sundial!”
As Nye recalled, speaking by telephone the other day from his office in Seattle, the other scientists said, “Bill, we’ve got a lot of clocks already, man—it’s a space program. Space program.” But Nye would not let the topic drop. Nye’s father, Ned, was a quartermaster who spent most of the Second World War in Japanese prison camps. To stay sane, Ned Nye built sundials out of fence posts, using pebbles to establish the hour lines. Each day, he’d observe when the shadow was shortest and mark noon in the dust, then trace the migration of those marks over time—the analemma—to keep track of the earth’s orbit, and thus the passing of seasons and years.
After the war, Ned Nye’s compulsion grew to fill his expanded horizons. As a travelling salesman for General Electric in the Washington, D.C., area, he would settle into a booth at a Hot Shoppe restaurant, order a club sandwich and an iced coffee, and then ask the waitress, “Know of any sundials around here?” He started an ill-starred business in “sand-dials” (sundials for the beach); suggested repurposing the Washington Monument as a giant sundial; and in 1969 published his opus, “Sundials of Maryland and Virginia.”
Similarly obsessed, Bill Nye finally persuaded his Cornell colleagues that sundials surrounded by gray rings would not only make photometric calibration possible but also mark the time, and “MarsDials” were built into the two Mars Exploration Rovers, the first of which, Spirit, will land on the Red Planet on January 3rd. Nye carried the day by pointing out that, because the Rovers would be roving about between Mars’ tropics—where the sun is more or less overhead in the sky—the sundials wouldn’t need a bulky triangular gnomon, or shadow-caster. They would require only a stick, like the ones his father used in the war.
The actual MarsDials are made of aluminum and are no larger than a human palm, but Nye believes that they will nonetheless inspire wonder. “Eratosthenes calculated the diameter of the Earth to within four per cent using the shadow from a stick,” he said. “Who knows what kids around the world will think of when they go to planetary.org and compare the shadow of a stick on Mars with the shadow of a stick on Earth? Or when they notice that the analemma on Mars is not figure-eight-shaped”—as it is on Earth—“but egg-shaped, because of Mars’ eccentric orbit?”
Nye hopes that the inhabitants of our world will coin a name for units of time on Mars (perhaps after they finally coin a name for the present decade on Earth). “A solar day on Mars is twenty-four earth hours and twenty-nine minutes,” he said. “So are the divisions ‘mours’? Or perhaps ‘duo-deimoses’”—the sixty Earth hours marked by two revolutions of Deimos, one of Mars’ moons. “Tiny Deimos has so little gravity,” he added enthusiastically, “you could stand on it and throw a tennis ball right into orbit!”
The MarsDials carry the epigraph “Two Worlds; One Sun,” and the word “Mars” in seventeen languages, including Mayan and Sumerian (in case the Rovers return to Earth through a wormhole and end up in 3000 B.C.). Nye also wrote a salute to future Mars explorers, inscribed alongside stick-figure drawings of dancing Earthlings, which are officially known as “sticksters.” His message says, in part, “We sent this craft in peace to learn of Mars’ past and to prepare for our future. To those who visit here, we wish a safe journey and the joy of discovery.”
Ned Nye died in 1997, and did not live to see his son’s sticks and sticksters. “As a child,” Nye said, “I would stand with my father on the beach in Delaware and stare at my shadow as the sun went down, watching it get longer and longer, infinitely long. When you understand how many stars are out there, more stars than there are grains of sand on the beach, you can think you’re just a speck orbiting a speck in the middle of specklessness. But there’s another way to look at it, which is that we have brains, and can use them to understand the universe. And I thought then that if I were out in space I could look back and see my shadow, the long shadow of little Bill.”
— Tad Friend