Gel-like substance found on Moon's far side by China's Yutu 2 rover analysed

Chinese scientists have finally published an analysis of a curious substance that was found on the moon and generated widespread interest after it was discovered by the Yutu-2 rover in 2019. The results of the study, named ‘Impact melt breccia and surrounding regolith measured by Chang’e-4 rover’ have been published as letter in the journal Earth and Planetary Science Letters. The discovery was made by a Yutu-2 team member in July last year during lunar day 8 of the rover’s mission. A Chinese-language science-outreach publication revealed the discovery on 17 August 2019 and described the substance as being “gel-like,” according to a  Space.com report. The scientists analysed data from Yutu 2’s panoramic and hazard avoidance cameras and its Visible and Near-Infrared Spectrometer (VNIS) instrument to come to the conclusion that the substance is actually made up of rock. [caption id=“attachment_8573601” align=“alignnone” width=“1280”] China’s Yutu 2 moon rover captured this image of glassy material from the edge of a small crater. Image courtesy: CNSA/CLEP[/caption] The team reportedly used a process called ‘spectral unmixing’ to break down the measured spectra from the VNIS instument to determine the likely composition and abundance of the material on the moon’s surface. The study authors have discovered the material to be a dark-greenish and glistening impact melt breccia, the sample measured being around 20 inches by 6 inches. This substance, an impact melt breccia, is the primary evidence that the area has been in a cataclysmic impact event, where the heat generated from the impact shatters and melts the target rock. Scientists say that the material resembles lunar impact melt breccia samples returned by NASA’s Apollo missions. A report in Science Alert adds that the substance is made predominantly of plagioclase (45 percent), pyroxene (7 percent) and olivine (6 percent), which are common minerals on the moon, apart from the glassy substance itself. On 2 January 2019, China’s Chang’e-4 lunar probe created history by becoming the first spacecraft to land on the far side of the Moon. Also read: **China's lunar probe has sent the first panoramic image of its landing site**