Chinese scientists have built an "artificial moon" research facility that
will enable them to simulate low-gravity environments using magnetism.
The facility, slated for official launch this year, will use powerful
magnetic fields inside a 2-foot-diameter (60 centimeters) 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 imitate the lunar surface, is the "first of its kind in
the world" and that it could maintain such low-gravity conditions for "as
long as you want."
Scientists plan to use the facility to test technology in prolonged
low-gravity environments before it is sent to the moon, where gravity is
just one-sixth of its strength on Earth. This will allow them to iron out
any costly technical kinks, as well as test whether certain structures will
survive on the moon's surface and assess the viability of a human settlement
there.
"Some experiments, such as an impact test, need just a few seconds [in the
simulator]," Li said. "But others, such as creep testing, can take several
days." A creep test measures how much a material will deform under a
constant temperature and stress.
According to the researchers, the inspiration for the chamber came from
Andre Geim, a physicist at the University of Manchester in the U.K. who won
the satirical Ig Nobel Prize in 2000 for devising an experiment that made a
frog float with a magnet.
The levitation trick used by Geim and now in the artificial-moon chamber
comes from an effect called diamagnetic levitation. Atoms are made up of
atomic nuclei and tiny electrons that orbit them in little loops of current;
these moving currents, in turn, induce tiny magnetic fields. Usually, the
randomly oriented magnetic fields of all the atoms in an object, whether
they belong to a drop of water or a frog, cancel out, and no material-wide
magnetism manifests.
Apply an external magnetic field to those atoms, however, and everything
changes: The electrons will modify their motion, producing their own
magnetic field to oppose the applied field. If the external magnet is strong
enough, the magnetic force of repulsion between it and the field of the
atoms will grow powerful enough to overcome gravity and levitate the object
— whether it's an advanced piece of lunar tech or a confused amphibian —
into the air.
The tests completed in the chamber will be used to inform China's lunar
exploration program Chang'e, which takes its name from 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 retrieved rock samples
from the moon's surface in 2020. China has also declared that it will
establish a lunar research station on the moon's south pole by 2029.
Originally published on
Live Science.
Tags:
Space & Astrophysics