Meteorites that crashed into the Martian surface last year exposed buried ice to the digital eyes of NASA spacecraft. Scientists have used those images to deduce that there is a lot more ice on Mars — and that it's closer to the equator — than previously thought. In fact, subterranean Martian ice should extend all the way down beyond 48 degrees of latitude, according to the model, which was published in Science Thursday. That happens to be where the Viking Lander 2 was in operation from 1976 to 1980. As part of its science program, the Lander dug a trench about 6 inches deep. The new model predicts that if it had gone an extra 3.5 inches — a bit longer than a credit card — it would have hit ice.