Phobos is twenty by twenty-three by twenty-eight kilometers and orbits much closer to its planet, less than six thousand kilometers above the surface. It crosses the Martian sky in only four and a half hours, hurtling from west to east like an artificial satellite (which it was once suspected to be) and rising again about six and a half hours later.
It is believed that Deimos and Phobos were originally asteroids, perhaps members of the great belt of minor chunks of rock and metal that orbits between Mars and the giant planet Jupiter. Eons ago they drifted close enough to be captured by the red planet’s gravitational field and fall into satellite orbits around it.
Thus, studying Phobos and Deimos can teach us much about the farther asteroids.
Most of the meteorites that have hit the Earth were originally asteroids. The Martian moons resemble the type of meteorites called by astronomers “carbonaceous chondrites.” Such meteorites have been found to contain not only carbon compounds, but water, locked in chemical combinations called “hydrates” within the meteorite’s rocky materials.
If the moons of Mars are rich in hydrates and carbon compounds, even though the water is not in liquid form, biologists will want to study the moons for signs of life or its precursors. Hydrates are immeasurably valuable to astronautical engineers, as well. They could supply life-giving water and oxygen. More important, water can be split into hydrogen and oxygen, which can be used for rocket propellants, which could cut in half the tonnages needed to be sent off Earth for any future missions to Mars.
The tiny moons of Mars, then, could become oases for space travelers where they can refresh life-support supplies and refuel rocket engines.
If they contain hydrates.
Which is why the Japanese geochemist and the Russian cosmonaut had left the Mars 2 spacecraft to begin the hands-on study of Deimos.
Tolbukhin said into his helmet microphone, “Five minutes to impact. I am arming the penetrator.” This was a rocket-powered grappling hook, designed to imbed itself into Deimos’s pitted surface and anchor the two men safely. Without it to tether them, the explorers could go flying off the tiny moon with every step they took, Deimos’s gravity was so negligibly low.
Still Konoye said nothing. He was no longer looking at the looming dark shape of Deimos. He stared instead at the enormous bulk of the red planet hanging overhead. He could not take his eyes off it.
The two men had left the Mars 2 spacecraft an hour earlier, decked in hard-shell pressure suits and tubular metal frames of mobility units wrapped around their bodies. They looked like brightly colored fat robots stuck inside individual jungle gyms. The mobility units contained personal equipment, life-support systems, and the thrust motors and propellants that allowed them to fly from the orbiting spacecraft to the Martian moon named after the Greek word for dread.
Slowly revolving a few kilometers away, the tethered Mars 1 and Mars 2 spacecraft looked like miniature models, white and silent, lifeless and desperately far off.
To Konoye, Deimos was an ugly, irregular, dark-gray lump of crater-pitted stone blotting out the stars, covering half the sky. Enormous. Menacing. And Mars itself seemed terrifyingly huge, crushingly massive. In his perspective, the ponderous enormity of the red planet loomed above him, glowering overhead, pressing down, squeezing the breath from his lungs. The three immense volcanoes of the Tharsis Bulge and the even bigger caldera of Olympus Mons seemed to be staring down at him like the four monstrous wide round eyes of a demon, staring balefully.
The Japanese geophysicist had trained for this moment for more than three years. He had gone through all the simulations on Earth and experienced long weeks of zero gravity aboard the space stations in Earth orbit. He had prepared himself thoroughly to lead the firsthand study of Mars’s two moons. Waiting for their turns behind him were a Russian geologist and an American geophysicist. But in this moment Japan was first.
Yet Konoye had not reckoned on that enormous expanse of red looming above him like a powerful, palpable force. This was no simulation. Mars hung over him and he could feel it squeezing down on him while its many-eyed demon glared at him, angry and demanding. Something in his childhood awakened and began screaming. Some long-forgotten nightmare tore at his mind. He had to get away. Get away!