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Dec. 31, 2018: At 2:43 p.m. EST, while many on Earth prepared to welcome the New Year, NASA’s OSIRIS-REx spacecraft, 70 million miles (110 million kilometers) away, carried out a single, eight-second burn of its thrusters—and broke a space exploration record.
The spacecraft entered into orbit around the asteroid Bennu, and made Bennu the smallest object ever to be orbited by a spacecraft.
Asteroids are rocky, airless worlds that orbit our Sun, but are too small to be called planets. Tens of thousands of these minor planets are gathered in the main asteroid belt, a vast doughnut-shaped ring between the orbits of Mars and Jupiter. Asteroids that pass close to Earth—and merit close watch—are called Near-Earth Objects, or NEOs.
The current known asteroid count is: .
Go farther. Explore Asteroids In Depth ›
Did You Know?
The total mass of all the asteroids in the main asteroid belt combined is less than that of Earth's Moon.