Reaching the asteroid with the poetic name 16 Psyche is no simple task.
Nevertheless, NASA decided to make the attempt and launch a mission to study the mysterious object up close. The asteroid is of particular interest to scientists because it appears to consist largely of metal, unlike most other known asteroids. Researchers also believe that the potato-shaped asteroid, measuring approximately 280 by 232 kilometers, could possibly be the exposed core of an early planet similar to Earth.
In October 2023, NASA's Psyche mission was launched aboard a spacecraft equipped with a suite of advanced scientific instruments. One of them is a magnetometer developed at DTU Space. The instrument will help scientists determine whether the asteroid has, or once had, a magnetic field similar to Earth's.
16 Psyche is located in the asteroid belt between Mars and Jupiter, hundreds of millions of kilometers from Earth. The journey is long and requires careful planning. The spacecraft does not travel in a straight line, but instead follows a winding trajectory through the Solar System in order to use energy as efficiently as possible.
A flyby of Mars during a 3.6 billion kilometer journey
Recently, the Psyche spacecraft performed a close flyby of Mars, using the planet's gravity to alter its trajectory and increase its speed by approximately 1,600 km/h. The so-called gravity assist maneuver saves energy by using the planet's gravitational field to accelerate the spacecraft.
"It is a milestone we have achieved, and it went well," says Professor José M. G. Merayo from DTU Space. He has led the work on the Danish magnetometer. The extremely sensitive magnetometer system is a key contribution to the mission.
"The magnetometer is still functioning perfectly without signs of aging after more than two years in space, which is very promising for the mission going forward".
When the mission reaches its destination as planned in the summer of 2029 after nearly six years of travel through space, the spacecraft will have traveled approximately 3.6 billion kilometers. This is when the actual exploration of one of the Solar System's most enigmatic asteroids will begin.
"Of course, we are looking forward to seriously beginning the exploration of 16 Psyche, but the magnetometer has already been active during large parts of the journey. We have therefore already completed the first measurements," says Professor José M. G. Merayo from DTU Space.
During the flyby, Psyche passed through the Martian magnetosphere while the magnetometer continuously collected measurements. Among other things, the instrument recorded the region where the solar wind is slowed down by Mars' magnetic environment.
"During the flyby, we were able to measure parts of Mars' magnetic field very precisely, and we continuously test the instrument throughout the mission," says José M. G. Merayo.
Possibly the result of a violent collision in the early Solar System
Unlike many other asteroids, 16 Psyche appears to consist primarily of metal.
Together with the other instruments onboard, the magnetometer will be used to investigate the asteroid's properties and provide new knowledge about how planets such as Earth formed early in the history of the Solar System.
Scientists therefore expect the mission to provide new insight into planetary cores and magnetic fields. One theory suggests that the asteroid may be the remains of the core of a forming planet that was later shattered by collisions during the early history of the Solar System.
The Psyche mission carries three scientific instruments in total: In addition to the magnetometer from DTU Space, the spacecraft carries a Gamma-Ray and Neutron Spectrometer provided by the Johns Hopkins Applied Physics Laboratory and a Multispectral Imager provided by Arizona State University.
This places DTU's instrument in highly qualified company as part of a trio of scientific instruments that may help answer some of the many questions surrounding the mysterious asteroid.
