NASA's first-ever mission created to visit an asteroid and return a sample of its dust back to Earth arrived Monday at its destination, Bennu, two years after launching from Cape Canaveral, Florida. At that age, it holds clues to how the Solar System formed, clues that aren't available here on Earth because of Earth's geological activity and living processes.
While most asteroids orbit between Mars and Jupiter in a band of space that's been dubbed the Asteroid Belt, Bennu is somewhat closer to Earth.
'We have arrived, ' technicians announced, spurring high-fives and clapping around the control room. During this period, OSIRIS-REx completed four maneuvers slowing the spacecraft's velocity from approximately 491 m/s to 0.04 m/s relative to Bennu, which resulted in the slower approach speed at the end of the video.
The craft has been travelling through space for more than two years.
But there's still a lot to learn about the object, saidUniversity of Arizona Planetary Scientist Bashar Rizk, who oversees three of OSIRIS-REx's cameras.
From that stage, the spacecraft will begin gradually tightening its orbit around the asteroid, spiralling to within just 1.8m of its surface. After a couple of flybys, OSIRIS-REx will settle into a steady orbit a few miles above the surface. Polycam is an eight-inch telescope that was the first camera to acquire Bennu and will be used to perform high-resolution mapping, while the Mapcam is used to search for plumes and satellites, and to take RGB color and near-infrared images for spectral imaging, topographic mapping, and color photography. "We have only scratched the surface when it comes to understanding asteroids".
Scientists look forward to having some real bits of asteroid back here on Earth to analyse. OSIRIS-REx will spend the next 18 months there, surveying the landscape and probing Bennu's chemical makeup before finally selecting what piece of the asteroid it wants to bring back home.
OSIRIS-REx's approach surveys of asteroid Bennu This montage includes images from two full rotation surveys of asteroid Bennu by OSIRIS-REx on 25 and 27 November.
OSIRIS-REx is NASA's first asteroid sample return mission, and the largest sample return since Apollo returned moon rocks.
Asteroids may have played a role in the origins of life here on Earth by delivering organic molecules to our planet in its early days.
Scientists hope they will get to examine the contents of an astronomical time capsule, with the carbon-rich material taken from Bennu's surface holding evidence from the beginning of the solar system 4.5bn years ago.
Osiris-Rex reached the "preliminary survey" phase of its mission on Monday, soaring to within 20km of the asteroid. It's easier to land on, and once on the surface, there will be plenty of material to sample. "You have a pristine sample of what the solar system was like billions of years ago", said Michelle Thaller, a spokeswoman for NASA's Goddard Space Flight Center. Along the way, the spacecraft performed a flyby of Earth on September 22, 2017 for a gravity assist to place the craft on its final trajectory to Bennu. Carbon is the hinge upon which organic molecules hang.
Water, another vital component to the evolution of life, may also be trapped in the asteroid's minerals. The robotic explorer Osiris-Rex pulled within 12 miles (19km) of the diamond-shaped object on Monday and will go into orbit around it on 31 December.
They hope the robot will collect at least 60g (two ounces) of dust and gravel from Bennu, using a 3m (10ft) mechanical arm to hoover up particles.
Asteroids are of extreme interest to scientists.
"When we understand Bennu, we will understand something fundamental about our solar system".