By Kaiya Palmer
There are many things we still do not know about the Earth, but we can use other celestial bodies such as asteroids to gain important insights into the inner workings of our planet. 16 Psyche is an M-type asteroid that presents an opportunity to make discoveries about iron cores and the formation of terrestrial planets like Earth.
What is 16 Psyche and why is it worth exploring?
16 Psyche is a potato-shaped asteroid that was discovered by Annibale de Gasparis in 1852 in Naples; it is also the 16th asteroid ever to be discovered, following 15 Eunomia. It has a radius of 113km (for comparison, Earth’s radius is 6,371km) and is located in the main asteroid belt between Mars and Jupiter. It is thought to be the leftover partial core of a protoplanet or planetesimal - a planet that did not survive. This conclusion is drawn from the composition of the asteroid: it is an M-type asteroid, which means it contains a lot of metal, particularly iron and nickel. This makes the total value of the materials within the asteroid extremely high, putting its worth at as much as $700 quintillion (the current global economy is worth around $90 trillion). Most bodies in our solar system are made up of mainly rock, ice, or gas, but 16 Psyche could be made up of up to 95% nickel and iron. This means that the asteroid offers a unique opportunity to gain insight into the formation of terrestrial planets such as Earth.
NASA wants to explore 16 Psyche because Earth’s core is unreachable, hidden deep below layers of mantle and crust; 16 Psyche is likely to be part of the core of a planet that was demolished, allowing scientists to gain a better understanding of iron cores and the formation of terrestrial planets.
The Psyche mission has been in motion since September 2015, when the Concept Study phase started. The mission consists of six phases, and will be completed in 2028. It is currently in phase D, and the spacecraft will be launched in August 2022 on a SpaceX Falcon Heavy rocket. The spacecraft will be fuelled by solar-electric propulsion and, after a 3.5 year journey, will arrive at its target in 2026. Instruments on the spacecraft will collect data during a 21-month orbit, which is split into four orbits at different heights to maximize the effectiveness of each instrument. This data will be sent back to Earth to be analyzed by scientists. These orbits will be completed in 2027, and space flight systems will be decommissioned to close out the mission in 2028.
Scientists hope to clarify whether the asteroid is a core or unmelted material as well as mapping out and determining the ages of regions of its surface. They also seek to find out how similar the conditions under which 16 Psyche formed are to the conditions under which Earth formed.
Psyche is the 14th mission in the NASA Discovery Program (a series of space exploration missions allowing us to better understand our universe), and shows great promise for groundbreaking discoveries.