Chinese scientists have built an "artificial moon" research facility that will allow them to simulate a low-gravity environment using magnetism.
The facility, scheduled to officially launch this year, will use powerful magnetic fields inside a 2-foot (60 centimeter) vacuum chamber to make gravity "disappear". The scientists were inspired by an earlier experiment that used magnets to levitate a frog.
Li Ruilin, a geotechnical engineer at the China University of Mining and Technology, told the South China Morning Post that the chamber, which will be filled with rocks and dust to mimic the lunar surface, is "the first of its kind in the world." and that it can maintain such low gravity conditions "for as long as you want".
Scientists plan to use the facility to test the technology in prolonged low gravity before it is sent to the Moon, where gravity is only one-sixth of what it is on Earth. This will allow them to iron out any costly technical failures, as well as to test whether certain structures on the surface of the Moon will survive, and to assess the viability of human settlement there.
Some experiments, such as the impact test, only take a few seconds [in the simulator]," Li said. "But others, like creep testing, can take days." The creep test measures how much a material will deform under constant temperature and load.
The inspiration for the camera came from Andre Game, a physicist at the University of Manchester in the UK, who won a satirical Ig Nobel Prize in 2000 for developing an experiment in which a frog swam with a magnet, according to the researchers.
The levitation trick used by Game, and now in the artificial moon chamber, is based on an effect called diamagnetic levitation. Atoms are made up of atomic nuclei and tiny electrons that revolve around them in little current loops; these moving currents in turn induce tiny magnetic fields. Usually, the randomly oriented magnetic fields of all atoms in an object, whether they belong to a drop of water or a frog, are neutralized, and material magnetism does not appear.
However, apply an external magnetic field to these atoms, and everything changes: the electrons change their motion, creating their own magnetic field, opposing the applied field. If the outer magnet is strong enough, the repulsive magnetic force between it and the atomic field will become powerful enough to overcome gravity and lift an object—whether it be an advanced piece of lunar technology or a bewildered amphibian—into the air.
The tests carried out in the chamber will be used to inform China's Chang'e lunar exploration program, named after the Chinese goddess of the moon. This initiative includes Chang'e 4, which landed a rover on the far side of the Moon in 2019, and Chang'e 5, which recovered rock samples from the Moon's surface in 2020. stations at the south pole of the moon by 2029.