Any magnetic object, such as a planet, that is immersed in a stream of ionized gas, known as plasma, produces a magnetosphere around it.
Because Earth has an internal magnetic field, it is encircled by a vast magnetosphere that stretches out into space, blocking harmful cosmic rays and particles from the sun and stars while allowing life to exist.
Scientists from Princeton, UCLA, and the Instituto Superior Técnico, Portugal, propose a method for studying smaller magnetospheres in the laboratory in Physics of Plasmas, published by AIP Publishing.
These mini-magnetospheres have been seen around comets and around particular regions of the moon, and it has been hypothesized that they could be used to propel spacecraft.
They’re useful as test beds for investigating larger magnetospheres, like as those found on planets.
To construct mini-magnetospheres in the lab, researchers have used plasma wind tunnels or high-energy lasers in the past.
These prior tests, on the other hand, were limited to 1D magnetic field measurements, which do not capture the entire 3D behavior that scientists need to understand.
“To circumvent these restrictions, we constructed a unique experimental platform on the Large Plasma Device (LAPD) at UCLA to explore mini-magnetospheres,” explained author Derek Schaeffer.
The magnetic field of the LAPD is combined with a fast laser-driven plasma and a current-driven dipole magnet on this platform.
The interplanetary magnetic field of the solar system is modelled by the LAPD magnetic field, while the solar wind is modelled by the laser-driven plasma and the Earth’s inherent magnetic field is modelled by the dipole magnet.
By merging data from tens of thousands of laser beams, motorized probes enable three-dimensional system scans.
This configuration has the advantage of allowing the magnetic field and other parameters to be carefully changed and controlled.
All evidence of a magnetosphere vanishes when the dipole magnet is turned off. A magnetopause may be identified when the dipole’s magnetic field is turned on, which is essential proof of the formation of a magnetosphere.
Computer simulations were used by the researchers to better understand and evaluate their experimental data, and they predicted the influence on the magnetopause.
Future investigations, including research using a cathode just built on the LAPD, will be guided by these simulations.
“The new cathode will enable quicker plasma flows, allowing us to analyze the bow shocks that have been recorded around several planets,” Schaeffer added.
Other studies will look into magnetic reconnection, a crucial phenomenon in the Earth’s magnetosphere in which magnetic fields annihilate, releasing massive amounts of energy.
To read our blog on “A new digital twin of the Earth will support the fight against climate change,” click here.
