Florida: NASA’s OSIRIS-REx spacecraft has its destination in its sights. On August 17, the probe took its first images of the asteroid 101955 Bennu, marking the beginning of the spacecraft’s approach after a nearly two-year space voyage.
The asteroid, just 500 meters wide, appears as a small bright dot moving against a starry background. Taking these images reassured the team that all the spacecraft’s navigation systems work, and that the asteroid was where the team thought it was.
OSIRIS-REx snapped the pictures from a distance of 2,186,228 kilometers, the closest-up images yet. When the asteroid was discovered in September 1999, it was 2,204,008 kilometers from Earth.
Over the next five years, OSIRIS-REx will map the asteroid’s surface, measure its gravity and pick up a sample of Bennu’s surface dust and send it back to Earth.
The asteroid sample is expected to return to Earth via free fall from space, until it reaches an altitude of 20.8 miles (33.5 km), when a first parachute will deploy. At 1.9 miles (3 km), the main parachute will be released, bringing the capsule with its precious cargo from Bennu in for a soft landing in the Utah desert on September 24, 2023.
On the other hand, a separate asteroid from a Japanese mission called Hayabusa2 will help reveal details of the early solar system and the origins of life and water on Earth.
Scientists also hope studying Bennu from afar and up close will help figure out what to do if an asteroid seems to be on a collision course with Earth.
That’s not an implausible scenario: Bennu is categorized as a potentially hazardous asteroid, and astronomers say it poses a slight risk — a one in 2,700 chances — of colliding with Earth in 2135.
It is also a carbon-rich asteroid, the kind of cosmic body that may have delivered life-giving materials to Earth billions of years ago.