Spacecraft Orbits Protoplanet in Asteroid Belt, a First

vesta-dawnOn Saturday, NASA’s Dawn spacecraft arrived at Vesta (pictured), a 330-mile-wide asteroid with a gravitational field that’s a mere 0.022 of Earth’s. It’s the first spaceprobe to orbit a large asteroid, known as a protoplanet, in the solar system’s asteroid belt.

While orbiting the asteroid, the 2,800 lb robotic spacecraft will conduct a year-long study of the big rock, where it will take pictures and gather data with two ultra-high resolution “framing cameras,” a visual and infrared spectrometer, as well as a gamma ray and neutron detector. With these sophisticated instruments, NASA hopes to gain an understanding of the origins and earliest conditions of our solar system. The research will also help determine why Vesta is the brightest asteroid in the solar system.

In a statement, NASA chief Charles Bolden said, “Dawn’s study of the asteroid Vesta marks a major scientific accomplishment and also points the way to the future destinations where people will travel in the coming years. President Obama has directed NASA to send astronauts to an asteroid by 2025, and Dawn is gathering crucial data that will inform that mission.”

According to, for its next destination in this two-asteroid tour, next year Dawn will fire its ion engines to send the craft toward Ceres, a larger spherical asteroid that’s also referred to as a dwarf planet. The spacecraft is scheduled to reach that destination by 2015.

Here’s an infographic detailing Dawn’s mission:

See how NASA's Dawn spacecraft will visit the asteroids Vesta and Ceres in this infographic.

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