Published on : 24/11/2021 – 03:46
The American space agency must take off on Tuesday a spacecraft due to strike the asteroid Dimorphos next fall in order to divert it from its trajectory. If this precise asteroid does not represent a danger for humanity, it is a test mission aimed at avoiding, one day, a potential collision with the Earth.
It’s a Hollywood-worthy scenario. NASA is preparing to take off on the night of Tuesday 23 to Wednesday 24 November an unprecedented mission. By projecting a vessel at 24,000 km / h against an asteroid, she hopes to change its trajectory and thus help humanity protect itself from a potential collision in the future.
This test “will be historic,” said Tom Statler, a NASA scientist participating in this mission, at a press conference. “For the first time, humanity will change the movement of a natural celestial body in space.” This is only a dress rehearsal, the target asteroid does not represent a threat to Earth. But the goal is taken very seriously by the US space agency.
It currently lists just over 27,500 asteroids of all sizes close to Earth and “none of them represents a threat in the next hundred years,” reassured Thomas Zurbuchen, director for scientific missions at the Nasa.
But experts estimate that they are only aware of 40% of asteroids measuring 140 meters or more – those capable of devastating an entire region – with the majority yet to be discovered. The idea is therefore to develop a technique to protect against it in the event of a future threat.
Ten short minutes
The mission, dubbed Dart (dart, in English), will take off from California’s Vandenberg base aboard a SpaceX Falcon 9 rocket, at 10:21 p.m. local Tuesday (6:21 a.m. GMT Wednesday).
The ship is smaller than a car, flanked by two long solar panels. It is due to strike next fall, in about ten months, an asteroid the size of a football field (about 160 meters in diameter), which will then be located eleven million kilometers from Earth.
The asteroid is called Dimorphos and is in fact a moon, orbiting a larger asteroid, named him Didymos (780 meters in diameter). To circle the large asteroid, Dimorphos currently takes 11 hours and 55 minutes. Scientists expect to reduce its orbit by about 10 minutes.
$ 330 million
“It’s a very small change but it might be all we need to deflect an asteroid colliding with Earth, if we ever have to, provided we find this asteroid early enough.” , explained Tom Statler.
The exact effect that the impact will have is not known at the moment because it depends in particular on the composition of the asteroid. It is this precise change in trajectory, which will then be measured using telescopes from Earth, that scientists want to determine. The results will be used in calculations to help define, in the future, how much mass must be projected against a given type of asteroid to cause sufficient deflection.
The total cost of the mission – the first interplanetary launched by Elon Musk’s company for NASA – is $ 330 million.