In March 1852, Italian astronomer Annibale de Gasparis discovered an asteroid orbiting between Mars and Jupiter, one of several he would find in his lifetime. He named it Psyche, after the Greek word for the soul. Many decades later, the name would take on new meaning. Scientists believe Psyche, one of the largest objects in the asteroid belt, may be the exposed metal core of an early planet, the soul of a celestial body.
Seven years from now, we’ll find out for sure. Earlier this week, NASA chose to fund an eponymous robotic mission to Psyche, scheduled to launch in 2023. The mission marks the first time spacecraft will visit a metallic asteroid, an extremely rare object in the solar system. Similar NASA missions have only visited rocky and icy worlds, like planets and other asteroids, like Vesta and Ceres. Scientists believe Psyche could have grown to be the size of Mars, but its rocky outer layers were smashed away by a series of collisions billions of years ago. What remains, a world made of metallic nickel and iron, is about the size of Massachusetts.
“By visiting Psyche, we can literally visit a planetary core the only way that humankind ever can,” Lindy Elkins-Tanton, the Psyche mission’s lead investigator, told reporters Wednesday. “It’s 1,800 miles to the Earth’s core, and the deepest humans have ever managed to drill is seven-and-a-half miles.”
Psyche is the only known round metal body in the solar system. The Psyche mission, led by researchers from Arizona State University, will launch in 2023 and reach its namesake by 2030. Over 20 months, the spacecraft will collect data about Psyche’s composition and topography, and, as is standard for robotic missions these days, return beautiful, GIF-able images of the asteroid. They hope Psyche will help them better understand planet formation, and learn more about Earth’s own iron core.
The Psyche mission is part of NASA’s Discovery program, which funds robotic spacecraft usually focused on a specific slice of science. The missions are capped at $450 million, making them pretty inexpensive, as far as solar system trips go. But the payoffs can be big. The Kepler space telescope has discovered hundreds of exoplanets since its launch in 2009; MESSENGER mission put the first spacecraft into Mercury’s orbit in 2011; and Dawn orbited one asteroid in 2011 before zooming over toward another last year, helping scientists understand the formation of rocky and icy bodies.
The Discovery announcement suggests a growing enthusiasm for asteroid research. NASA has also approved funding for the Lucy mission, which will launch in 2021 to explore the Trojan asteroids, so called because they’re named after figures in the mythical war, that share the orbit Jupiter takes around the sun.