The Lucy probe passes close to Earth before heading towards Jupiter’s asteroids

The Lucy probe passes close to Earth before heading towards Jupiter’s asteroids

His 12-year mission involves returning to Earth’s orbit to exploit the gravitational probe

Today, October 16, NASA’s Lucy probe, the first mission ever launched to Jupiter’s Trojan asteroids, will return to Earth skimming the atmosphere, passing into a very low orbit, only 350 kilometers high. Launched on October 16, 2021, Lucy will get the boost she needs from our planet’s gravitational slingshot to reach these asteroids never seen before. His journey will last another 11 years, the Trojan asteroids are on the same orbit as Jupiter accompanying him on his journey around the Sun.

The gravitational slingshot of the Earth will position Lucy on a new orbit that after two years will bring her back to our planet from which she will receive a second gravitational push that will give Lucy the speed to reach the main asteroid belt, between Mars and Jupiter, where she will observe the asteroid Donaldjohanson. Very little is known about the masses, chemical composition, rotation or other physical parameters of Jupiter’s Trojan asteroids which are the same age as the solar system and could therefore tell us a lot about its formation.

In this belt Lucy will pass close to six meteorites, gathering valuable data and information: Eurybates and its satellite Queta, Polymele and its satellite, Leucus and Orus. After this observation she will return to Earth to receive the third push, in 2030, which will allow her to reach a laro swarm of meteorites, this time at the tail of the planet Jupiter, to study a specific pair Patroclus and Menoetius, father and son in Greek mythology. , which make their journey in space gravitationally linked to each other.

Passing by the Earth, Lucy will pass on an orbit lower than even the International Space Station, so she will have to cross an area full of satellites and debris already in orbit around the planet. NASA has developed some procedures to anticipate any potential danger and, if necessary, to perform a small correction to avoid a collision. “The Lucy team has prepared two different maneuvers,” says Coralie Adam, deputy head of the Lucy navigation team of KinetX Aerospace in Simi Valley, California. “If the team detects that Lucy is at risk of colliding with a satellite or piece of debris, then, 12 hours before the closest approach to Earth, the spacecraft will perform one of these, altering the approach time by two or more. four seconds. This is a small correction, but it is enough to avoid a potentially catastrophic collision ”.

Lucy will first be visible to ground observers in Western Australia at around 6:55 pm local time. It will fly over the Pacific Ocean in the Earth’s shadow cone and emerge from the darkness of the Earth over the western United States from where it will be visible even with the help of a simple binolculum.

“The last time we saw the spacecraft, it was on the launch pad,” said Hal Levison, Lucy’s principal investigator at the Southwest Research Institute (SwRI) in Boulder, Colorado. “And this time Lucy will be in the sky.” As she passes close to the Moon, Lucy will take a few more calibration images before continuing into interplanetary space. “I am particularly excited about the images Lucy will take of the Moon,” said John Spencer, deputy scientist of the SwRI project: “This will be the first opportunity to calibrate Lucy’s ability to detect craters by comparing it to previous observations of the Moon by other space missions “.