NASA's Osiris-Rex probe ready to touch the asteroid Bennu: it will 'bomb' it to collect samples of its rock to take to Earth.
It is an event expected all over the world because it is the first time that an American probe will attempt the undertaking, scheduled to start at about 11.00 pm Italian and which will last more than four hours.
On ANSA Scienza the images of the live streaming with NASA.
Collecting a sample directly from an asteroid offers a unique opportunity to study rocks that date back to the formation of the Solar System more than 4.5 billion years ago.
"While the planets and moons have changed over the millennia, many of these little bodies have not," said Lori Glaze, head of NASA's division of planetary sciences.
"The asteroids - he added - are like time capsules that can provide fossil evidence of the birth of our Solar System".
The probe, launched in 2016, will attempt to collect samples from an area in the center of the Nightingale site, 16 meters in diameter, selected because it is rich in fine-grained material, but boulders the size of a building loom over the region.
To collect the samples, the probe, the size of a van, will have to attempt to land on an area the size of some parking space.
The collection of samples will last a total of 4.5 hours and involves three maneuvers to reach the surface of the asteroid.
The
descent sequence
begins with Osiris-Rex firing the thrusters to leave its safe orbit approximately 770 meters from Bennu's surface and descend towards the ground.
Arriving at a height of 125 meters, the probe will perform another maneuver to adjust the position and regulate the speed.
About 11 minutes later, at an altitude of 54 meters, the spacecraft will brake and start targeting its target.
It will then descend to the surface, touch it for
less than 16 seconds,
and fire one of its three pressurized nitrogen cylinders.
The gas will lift the material off Bennu's surface as the probe moves away.
Reached a safe distance, the probe will extend its 3.4 meter long robotic arm to collect samples:
60 grams of dust and gravel to
be brought to Earth by 2023
