Washington (AFP)

Lucy, NASA's first mission to the Trojan asteroids, located in the orbit of Jupiter, is due to take off Saturday morning from Florida, embarking on a 12-year journey that should provide a better understanding of the formation of our solar system.

The Atlas V rocket responsible for propelling the spacecraft is scheduled to take off on Saturday at 5:34 a.m. local time (9:34 a.m. GMT) from Cape Canaveral.

The craft will be the first solar-powered to venture this far from the Sun, and will observe more asteroids than any other spacecraft before it - eight in all.

Each of these asteroids must "deliver a part of the history of our solar system, of our history," Thomas Zurbuchen, director of the science division of the US space agency, told a press conference.

Around 2025, the spacecraft will first fly over an asteroid in the main asteroid belt, located between Mars and Jupiter.

Then he will visit seven Trojan asteroids, including the last two in 2033.

The largest of them is about 95 km in diameter.

The spacecraft will approach the selected objects at a distance of only 400 to 950 kilometers, depending on their size, and at a speed of approximately 24,000 km / h.

The Trojan asteroids, of which about 7,000 are known, evolve around the Sun in two groups, one preceding Jupiter, the other following it.

"One of the surprising things about Trojan asteroids is that they are very different from each other, especially their color: some are gray, some are red," said Hal Levison, senior researcher for this mission.

"We think their color indicates where they're from."

Researchers want to study their geology, composition, and precise density, mass and volume.

The mission was named Lucy in reference to the Australopithecus fossil discovered in Ethiopia in 1974, which helped shed light on the evolution of humanity - NASA here wishing to shed light on the evolution of the solar system.

The researchers who found this skeleton were listening at the time to the Beatles song "Lucy in the sky with diamonds".

"We do take a diamond on board," smiled Phil Christensen, responsible for the scientific instrument called L'TES, which contains the gemstone.

This instrument will measure infrared light, which will determine the surface temperature of the asteroids.

"By comparing these night and day measurements, we can determine if the surface is made of boulders, or fine dust and sand," he explained.

Indeed, the rock cools less quickly than the sand at night.

The total cost of the mission, including its 12 years of operations, is $ 981 million.

© 2021 AFP