Asteroid Mission Aims to Explore Mysteries of Earth's Core

NASA is launching a spacecraft in October 2023 to visit the asteroid Psyche, a metal-rich asteroid. The mission with the same name, Psyche, will study the asteroid, which is located in the main asteroid belt between Mars and Jupiter, to learn more about our solar system, including the core of our own planet.

Read more to find out what we will learn from the Psyche mission. Get to know the science behind the mission and follow along in the classroom using STEM teaching and learning resources from NASA.

This illustration depicts the 140-mile-wide (226-kilometer-wide) asteroid Psyche, which lies in the main asteroid belt between Mars and Jupiter.

Credit: NASA/JPL-Caltech/ASU

Asteroids are thought to be rocky remnants that were left over from the early formation of our solar system about 4.6 billion years ago. Of the more than 1.3 million known asteroids in our solar system, Psyche’s metallic composition makes it unique to study. Ground-based observations indicate that Psyche is a giant metal-rich asteroid about one-sixteenth the diameter of Earth’s Moon and shaped like a potato. Scientists believe it might be the partial nickel-iron core of a shattered planetesimal – a small world the size of a city that is the first building block of a planet. Asteroid Psyche could offer scientists a close look at the deep interiors of planets like Earth, Mercury, Venus, and Mars, which are hidden beneath layers of mantle and crust.

We can’t see or measure Earth’s core directly – it is more than 1,800 miles (3,000 kilometers) below the surface and we have only been able to drill about 7.5 miles (12 kilometers) deep with current technology. The pressure at Earth’s core measures about three million times the pressure of the atmosphere at the surface, and the temperature of Earth’s core is about 9,000 degrees Fahrenheit (5,000 degrees Celsius), so even if we could get science instruments there, the hostile conditions would make operations practically impossible. The Psyche asteroid may provide information that will allow us to better understand Earth’s core, including its composition and how it was created. The asteroid is the only known place in our solar system where scientists might be able to examine the metal from the core of a planetesimal.

The Psyche mission's science goals are to understand a previously unexplored building block of planet formation (iron cores); to explore a new type of world; and to look inside terrestrial planets, including Earth, by directly examining the interior of one of these planetary building blocks, which otherwise could not be seen. The science objectives that will help scientists meet these goals include determining if asteroid Psyche is actually leftover core material, measuring its composition, and understanding the relative age of Psyche's surface regions. The mission will also study whether small metal-rich bodies include the same light elements that are hypothesized to exist in Earth's core, determine if Psyche was formed under similar or different conditions than Earth's core, and characterize Psyche's surface features.

The Psyche mission will launch on a SpaceX Falcon Heavy rocket. Psyche’s solar arrays are designed to work in low-light conditions because the spacecraft will be operating hundreds of millions of miles from the Sun. The twin plus-sign shaped arrays will deploy and latch into place about an hour after launch from Earth in a process that will take seven minutes for each wing. With the arrays fully deployed, the spacecraft will be about the size of a singles tennis court. The spacecraft’s distance from the Sun will determine the amount of power it can generate. At Earth, the arrays will be able to generate 21 kilowatts, which is enough electricity to power three average U.S. homes. While at asteroid Psyche, the arrays will produce about two kilowatts, which is a little more than what is needed to power a hair dryer.

An illustration of NASA’s Psyche spacecraft and its vast solar arrays.

Credit: NASA/JPL-Caltech/ASU

At left, xenon plasma emits a blue glow from an electric Hall thruster identical to those that will propel NASA's Psyche spacecraft to the main asteroid belt. On the right is a similar non-operating thruster. Full image and caption

Credit: NASA/JPL-Caltech

The spacecraft will rely on the launch vehicle’s large chemical rocket engines to blast off the launchpad and escape Earth’s gravity, but once in space, the Psyche spacecraft will travel using solar-electric propulsion. Solar-electric propulsion uses electricity from the solar arrays to power the spacecraft’s journey to asteroid Psyche. For fuel, Psyche will carry tanks full of xenon, the same neutral gas used in car headlights and plasma TVs. The spacecraft’s four thrusters – only one of which will be on at any time – will use electromagnetic fields to accelerate and expel charged atoms, or ions, of that xenon. As those ions are expelled, they will create thrust that gently propels Psyche through space, emitting blue beams of ionized xenon. The thrust will be so gentle that it will exert about the same amount of pressure you’d feel holding three quarters in your hand, but it’s enough to accelerate Psyche through deep space. You can read more about ion propulsion in this Teachable Moment.

The spacecraft, which will travel 2.2 billion miles (3.6 billion kilometers) over nearly 6 years to reach its destination, will also use the gravity of Mars to increase its speed and to set its trajectory, or path, to intersect with asteroid Psyche’s orbit around the Sun. It will do this by entering and leaving the gravitational field of Mars, stealing just a little bit of kinetic energy from Mars’ orbital motion and adding it to its own. This slingshot move will save propellant, time, and expense by providing a trajectory change and speed boost without using any of the spacecraft’s onboard fuel.

Upon arrival at Psyche, the spacecraft will spend 26 months making observations and collecting data as it orbits the asteroid at different altitudes. Unlike many objects in the solar system that rotate like a spinning top, the asteroid Psyche rotates on its side, like a wheel. Mission planning teams had to take this unique characteristic into account in planning the spacecraft's orbits. The different orbits will provide scientists with ideal lighting for the spacecraft's cameras and they will enable the mission to observe the asteroid using different scientific instruments onboard.

The spacecraft will map and study Psyche using a multispectral imager, a gamma-ray and neutron spectrometer, a magnetometer, and a radio instrument (for gravity measurement). During its cruise to the asteroid, the spacecraft will also test a new laser communication technology called Deep Space Optical Communication, which encodes data in photons at near-infrared wavelengths instead of radio waves. Using light instead of radio allows the spacecraft to send more data back and forth at a faster rate.

Follow Along

Psyche is scheduled to launch no sooner than October 5, 2023 from Kennedy Space Center in Florida. Tune in to watch the launch on NASA TV.

Visit the mission website to follow along as data are returned and explore the latest news, images, and updates about this mysterious world.

The Psyche mission is a great opportunity to engage students with hands-on learning opportunities. Explore these lessons and resources to get students excited about the STEM involved in the mission.

• Article for Kids: Asteroid or Meteor: What's the Difference?
• Article for Kids: What Is an Asteroid?
• Article for Kids: Why Does the Moon Have Craters?
• Article for Kids: What Is an Impact Crater?

• Psyche Mission
• Asteroid Watch
• Center for Near-Earth Object Studies
• NASA Space Apps Challenge

• Psyche News Archive
• Articles: Asteroid News from JPL

• Psyche Image Gallery

• Psyche Mission Video

• Eyes on Asteroids

• Print a 3D Model of the Psyche Spacecraft
• Create a Psyche Lego Model
• Create a Model of the Psyche Asteroid