Mars mapped to the metre

By Oliver Morton

It is a desert plain, caramel-smooth and windswept-empty. To its north rises a mountain taller than Mont Blanc, Mount Rainier or Fuji-san and though, because it is also wider, its sides are less steep and prospects less dramatic, it is still an impressive thing. A massive central shoulder, banded with rocks of different ages, juts out over the plain; to its side, the mountain’s forest-free flanks are cut with canyons. The summit—whittled away by the wind but a stranger to snow—sits farther back, hidden from view. Both plain and mountain are ringed by a wall four kilometres high and almost 500 kilometres long, the rim of a crater the size of Wales. Above the landscape is a washed-out, alien sky. At the right time of year, the Earth hangs over that horizon-rim at twilight, a blueish evening star.

This is Gale crater, a part of Mars with which some of the inhabitants of that evening star have made an appointment. As this page went to press in late November, a six-wheeled rover called Curiosity was due to be thrown there by a 500-tonne Atlas V rocket. If all goes well—a substantial if, as Mars missions often don’t; a Russian one failed to get beyond Earth’s orbit in early November—then next August a complex system of parachutes and retrorockets will lower the rover through the thin Martian atmosphere to its destination. It will trundle across the plain to the ancient rocks of the mountain’s base and start a slow ascent. It will sniff the air and take samples of rock and soil to analyse in its on-board laboratory. With the help of an orbiting intermediary, it will send back to Earth a torrent of pictures, from the panoramic to the microscopic.