A large asteroid in our solar system called 2 Pallas is actually a protoplanet - a moon-sized body that might have formed into a full-sized planet under different circumstances, scientists report.
2 Pallas, with a diameter of 165 miles (265 km), is one of the largest bodies in the asteroid belt between Mars and Jupiter. A recent study of the object's surface and shape based on data from the Hubble Space Telescope suggests that 2 Pallas is more dynamic than the chunks of rock that make up most of the asteroid belt.
"When you think asteroid, you think a small rubble pile, and this isn't that," said study leader Britney Schmidt, a planetary physics graduate student at UCLA. "These objects are transitions between planets and asteroids. They're almost like mini planets."
Although not perfectly round, 2 Pallas has enough gravity to have become almost a sphere shape, much rounder than most of the rocky asteroids around it.
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