2023-10-12 19:39:10
Kennedy Space Center (United States) (AFP) – NASA is preparing to launch a mission on Friday to the distant asteroid Psyche, a world made of metal never before studied, which scientists believe could be the nucleus of an ancient celestial body.
Published on: 10/12/2023 – 9:39 p.m. Modified on: 10/12/2023 – 9:37 p.m.
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The Psyche probe is scheduled to take off at 10:19 a.m. local time (2:19 p.m. GMT) from the Kennedy Space Center in Florida, aboard a SpaceX Falcon Heavy rocket.
But the weather promises to be capricious, with only a 40% chance of favorable weather for takeoff. A new shooting opportunity is planned for Saturday if necessary.
Humanity has already visited worlds made of rocks, ice or gas. But “this will be the first time that we will visit a world that has a metallic surface,” Lindy Elkins-Tanton, scientific manager of the mission, said at a press conference.
The journey to get there will be long: Psyche is located in the outer part of the asteroid belt, between the orbits of Mars and Jupiter. The NASA probe will travel some 3.5 million kilometers to reach it, with an arrival date planned for summer 2029.
Thanks to the light reflected from its surface, scientists know that Psyche is very dense, and that it is made of metal, as well as some other material — perhaps rock.
But “we don’t know what Psyche looks like,” explained the researcher. “I often joke that it’s shaped like a potato, because potatoes come in lots of different shapes, so I’m not wrong,” she laughed.
A SpaceX Falcon Heavy rocket on October 11, 2023 before takeoff for NASA’s Psyche mission © CHANDAN KHANNA / AFP
Scientists believe that Psyche, which is more than 200 km long, could be the core of an ancient celestial body, whose surface was torn away by asteroid impacts.
The Earth, like Mars, Venus, or Mercury, has a metallic core. But “we’re never going to see these cores, it’s way too hot, way too deep,” said Lindy Elkins-Tanton. The mission to Psyche is therefore “our only way to see a core”.
– Volcanoes, crevasses, craters? –
Psyche was formed some 4.5 billion years ago, at the birth of our solar system. It may have experienced volcanic eruptions, of which traces could remain in the form of ancient lava flows.
Then, as Psyche cooled, its contraction may have caused huge cracks to form.
Scientists are also eager to see what the craters look like on a metallic celestial body: the material propelled by the impact of asteroids could have remained frozen in the air and formed sort of points.
The probe will remain in orbit around Psyche for a little over two years to study it, alternating between several altitudes.
Photographs provided by NASA of a Hall effect thruster, off on the right and on on the left © Handout / NASA/JPL-Caltech/AFP
It will use three scientific instruments: multispectral imagers to photograph it, spectrometers to determine its composition, and magnetometers to measure its magnetic field.
To move, the probe will also use Hall effect thrusters, a first for interplanetary travel.
These motors use electricity provided by the probe’s solar panels to obtain ions of a noble gas (xenon gas), which are then accelerated by passing through an electric field. These are then expelled at very high speed, “five times faster than the fuel coming out of a conventional rocket,” said David Oh, NASA engineer. Which produces the necessary thrust.
“It’s the kind of thing we heard about in Star Wars and Star Trek, but today we’re making the future a reality,” he said.
The Psyche mission will also test a communication system with lasers, which should make it possible to transmit more data than radio communications.
© 2023 AFP
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