Nasa’s Psyche spacecraft rocketed away on Friday on a six-year journey to a rare metal-covered asteroid.
Most asteroids tend to be rocky or icy, and this is the first exploration of a metal one. Scientists believe it may be the battered remains of an early planet’s core, and could shed light on the inaccessible centers of Earth and other rocky planets.
SpaceX launched the spacecraft into the midmorning sky from Nasa’s Kennedy Space Center in Florida. Named for the asteroid it’s chasing, Psyche should reach the huge, potato-shaped object in 2029.
After decades of visiting faraway worlds of rock, ice and gas, Nasa is psyched to pursue one coated in metal. Of the nine or so metal-rich asteroids discovered so far, Psyche is the biggest, orbiting the sun in the outer portion of the main asteroid belt between Mars and Jupiter alongside millions of other space rocks. It was discovered in 1852 and named after Greek mythology’s captivating goddess of the soul.
“It’s long been humans’ dream to go to the metal core of our Earth. I mean, ask Jules Verne,” said lead scientist Lindy Elkins-Tanton of Arizona State University.
“There’s one way in our solar system that we can look at a metal core and that is by going to this asteroid.”
Astronomers know from radar and other observations that the asteroid is big – about 144 miles (232km) across at its widest and 173 miles (280km) long. They believe it’s brimming with iron, nickel and other metals, and quite possibly silicates, with a dull, predominantly gray surface likely covered with fine metal grains from cosmic impacts.
Scientists envision spiky metal craters, huge metal cliffs and metal-encrusted eroded lava flows tinted greenish-yellow from sulfur.
“There’s a very good chance that it’s going to be outside of our imaginings, and that is my fondest hope,” she said.
Believed to be a planetary building block from the solar system’s formation 4.5bn years ago, the asteroid can help answer such fundamental questions as how did life arise on Earth and what makes our planet habitable, according to Elkins-Tanton.
On Earth, the planet’s iron core is responsible for the magnetic field that shields our atmosphere and enables life.
Led by Arizona State University on Nasa’s behalf, the $1.2bn mission will use a roundabout route to get to the asteroid. The van-size spacecraft with solar panels big enough to fill a tennis court will swoop past Mars for a gravity boost in 2026. Three years later, it will reach the asteroid and attempt to orbit around it, circling as high as 440 miles and as close as 47 miles until at least 2031.
