With an expected resurgence in lunar missions in the coming years, Purdue University engineer Carolin Frueh is researching how to minimize the impact of space debris as it increases in the cislunar region.

Data collected by China’s Chang’E-4 Moon lander suggests there is a region of reduced galactic cosmic rays (GCRs) in a sector of the lunar orbit. This “cavity” is formed by an unexpected extension of the magnetic field produced by Earth, according to Wensai Shang and colleagues. Earth’s magnetic field protects us from the highly energetic particles of GCRs that speed through the solar system and likely originate in supernova remnants. Scientists previously thought GCRs were uniformly distributed in space between the Earth and the Moon. After analyzing data collected by the Chang’E-4 lander’s LND (Lunar Lander Neutron and Dosimetry) experiment for 31 lunar cycles, Shang et al. conclude that there is a GCR cavity in Earth-Moon space shaped by the Earth’s magnetosphere reaching at least to the lunar orbit on the dayside of Earth. The researchers suggest that the Moon spends about two days each lunar revolution crossing this lower radiation zone during the pre-noon time period. Shang et al. suggest that this region could provide a valuable opportunity for lunar and deep-space missions to reduce radiation exposure that can damage instruments and threaten human health. Further work will be needed to determine the cavity’s full extent and behavior.

Earth’s magnetic field acts as a vital shield against radiation arriving from space, but it is not constant. A new international study has examined how a reduction of the magnetic field similar to the Laschamps excursion would affect aviation on routes such as Helsinki–Dubai and Helsinki–New York if it occurred today.