Chang’e-4 , the first mission to ground on thefar side of the Moon , is helping researchers realize what the interior of our natural orbiter is like . The lander touched down in the South Pole - Aitken ( SPA ) drainage area , one of the big know impact craters in the Solar System .
This positioning is crucial to the foreign mission . The 2,500 - klick ( 1,550 - international mile ) crater is expected to contain material from the Moon ’s inside . The ancient impact rive the encrustation and brought to the control surface rocks from the mantle . To take the composition of these rocks , the lander deploy Yutu-2 ( Jade Rabbit ) , a rover equipped with a visible and infrared spectrometer .
The lander and rover are deposit in the Von Kármán crater within the SPA , which is middling flavourless although there are some deep impact crater around . The scouter ’s first watching were made on the rocks in the 2-dimensional area and they were quite queer . Researchers were bear to find an teemingness of the mineral olivine , the principal component of the Earth ’s upper mantle . Surprisingly , in the 2-dimensional champaign of the SPA , the mineral is not common at all .
" The absence of abundant olivine in the SPA DoI remain a enigma , " Li Chunlai , a professor at the National Astronomical Observatories of the Chinese Academy of Sciences ( NAOC ) , said in astatement . " Could the predictions of an olivine - rich lunar mantle be incorrect ? "
The first determination were only part of the picture . The team performed some spectral analytic thinking of textile from smaller and deeper wallop within the SPA and managed to get more olivine . Based on this , the research worker suggest that olivine and another mineral called pyroxene make up the mantle of the Moon in around equal composition . The finding are reported inNature .
" Understanding the composition of the lunar curtain is decisive for testing whether a magma ocean ever existed , as posit , " explained Li . " It also help advance our understanding of the thermic and magmatic evolution of the Moon . "
The more olivine - rich rocks are believed to have come from the nearby Finsen impact volcanic crater , which is 72 kilometers ( 45 miles ) in diam and much deeper than the SPA . Yutu-2 will continue to study these rocks to in full realise their origin and abundance , and will even assess the theory of accumulate them and bringing them back to Earth in a future missionary post .
