Image credit: NASA/Goddard/University of Arizona

Artist’s concept of the OSIRIS-REx spacecraft at Bennu.

Our solar system is a busy place. We have the sun, eight planets, at least five dwarf planets, and more than 170 moons. But we also have millions of comets and asteroids. One of these asteroids is named Bennu. Bennu is large, and it orbits the sun near the Earth’s orbit. This asteroid is also very old. Scientists want to study Bennu to learn about the early solar system.

NASA scientists will study Bennu with a spacecraft named OSIRIS-REx. OSIRIS-REx stands for Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer. That long name means the mission will do several important things. For example, OSIRIS-REx will perform experiments to see what Bennu is made of. This is cool because the materials in an asteroid could one day be useful resources here on Earth!

OSIRIS-REx will also explore the asteroid’s surface and learn about the size and shape of Bennu. This and other information will help scientists understand what might happen if an asteroid collides with Earth.

All of this exciting work will take a long time—almost seven years—to complete. OSIRIS-REx launched on September 8, 2016. However, Bennu is really far away. OSIRIS-REx won’t arrive there until 2018. When it finally arrives, OSIRIS-REx will begin mapping the asteroid’s surface. It will take a whopping 505 days for OSIRIS-REx to complete this map!

Later, in July 2020, OSIRIS-REx will fly very close to Bennu. It will use a robotic arm to collect some rocks and dust from the asteroid’s surface. OSIRIS-REx will send that sample back to Earth. But since Bennu is so far away, the sample won’t arrive on Earth until sometime in 2023.

In its long seven-year journey, OSIRIS-REx will be trying to answer one main question: Where did we come from? On Bennu, maybe we’ll find the building blocks for life and learn more about the chemistry that started life on Earth. No matter what we discover on Bennu, we are sure to learn more about the history of our vast and busy solar system!

Learn more about asteroids at the NASA Space Place: