Very small worlds can do very big things—providing you're willing to grade on a curve. Take the dwarf planet Ceres, the largest body in the asteroid belt, which is currently being orbited by the Dawn spacecraft. Ceres is just 591 miles (952 km) across—or 73% of the size of Texas—with only 3% of Earth's gravity. If you weigh 150 lbs. here, you'd weigh 4.5 lbs. there.
But Ceres has a mountain—and it's a whopper, as evidenced by this latest image sent home by Dawn, orbiting at an altitude of 915 miles (1,470 km). The mountain stands 4 miles (6 km) tall—a bit shorter than Mt. Everest, which tops out at 5.49 miles (8.83 km). But context is everything. A 4-mile-tall mountain on a tiny world like Ceres is the equivalent of a 49.8-mile-tall (80.1 km) mountain on Earth, or nine times taller than a pipsqueak like Everest. The Ceres mountain is not terribly active—at least as evidenced by the absence of debris at its base—but it is scored by a bright streak running down its side, which suggests some kind of dynamic processes at least in the past.
Every pixel of the Dawn image represents 450 ft. (140 m) of Ceres' surface, which is already an impressively granular resolution. In the future, the spacecraft will approach the surface at just 25% of its current altitude, improving image detail dramatically. Whatever secrets Ceres is keeping Dawn may soon reveal.
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NASA/JPL/Space Science Institute