An SUV-sized spacecraft, loaded with instruments and an extendable robotic arm, will soon be sent to the Bennu asteroid. He promises to return with an unprecedented souvenir: samples of extraterrestrial soil that could give us valuable clues to the Universe’s past.
Asteroid Bennu, a rounded black rock larger than the Empire State Building, will be the target of a NASA probe that will lift off Thursday from Cape Canaveral, Florida. A two-year journey (190 million kilometers), at the end of which the craft, named Osiris-Rex, will land on the asteroid 101955 Bennu, probably composed of remnants of the early universe.
Arrived near the large stone, the spacecraft will spend some time remotely analyzing the surface of the asteroid, using a series of instruments designed and built by more than 50 MIT students. A spectrometer will analyze the interaction of X-rays from the sun with the ground in order to identify the chemical elements present on the surface of Bennu. The instrument will also allow researchers to determine key locations for the robotic arm to reach and grab a sample. Sample that will return to Earth in 2023.
Bennu is shaped like a ball, with a gritty equatorial circumference. At least, that’s what the researchers think. Still, the place would be ideal to take a sample. Of course, flying to another world isn’t easy. Neither is collecting samples. We know that the asteroid rotates every four hours. A rotation slow enough for the spacecraft to reach and suck up samples, using nitrogen gas. « We are a kind of vacuum cleaner of space », declared a few hours ago Dante Lauretta, principal investigator of this mission.
Bennu is a potentially dangerous asteroid. There’s a tiny chance it could hit the planet in 150 years or more… About a tenth of 1 percent, according to the researcher. “It would be a major natural disaster, but not a knockout for the Earth or life as we know it,” he stressed.
This mission should help scientists better understand the evolution of asteroids. Charcoal-colored Bennu, a sign that the rock contains carbon that dates back to the origin of the solar system, 4.5 billion years ago. If so, Bennu would be a veritable time capsule that could help us understand how life may have sprung up on Earth and, eventually, elsewhere in the stellar quarter.