Almost a year after Chandrayaan 3 landed on the Moon, scientists in India have released the findings of studies carried out by one of the instruments on the rover module.
The findings were published in the journal Nature recently.
The data collected by the Alpha Particle X-ray Spectrometer (APXS) also contain new information about the elemental composition of the lunar surface that can help to better understand the evolution of the Moon.
Alpha Particle X-ray Spectrometer (APXS) findings:
Scientists have reported three key findings.
-The terrain around Chandrayaan 3’s landing sight is fairly uniform.
-The Moon’s crust was formed layer by layer, which adds weight to the lunar magma ocean (LMO) hypothesis.
-The topsoil around the lunar south pole has a greater-than-expected sprinkling of minerals which compose the lower layers of the lunar crust.
LMO hypothesis(Lunar Magma Ocean Hypothesis)
-The Moon is thought to have been formed after a large asteroid collided with Earth some 4.5 billion years ago. Scientists hypothesise that in its early life, the Moon’s surface was made up entirely of an ocean of magma.
-As this ocean cooled over millions of years, heavier silicon- and magnesium-rich minerals such as olivine and pyroxene sank to the lower levels of the lunar crust and its upper mantle (which is generally the largest layer inside a planetary body, bounded by the planet’s core on the inside and the crust on the outside). Lighter minerals, composed of calcium- and sodium-based compounds, floated to the top and formed the upper crust.
-The findings of Chandrayaan 3’s APXS take this hypothesis a step further. They support a class of models under the umbrella of the LMO hypothesis which theorises a stratified lunar crust — where 80-90% of the upper crust is believed to be composed of iron, magnesium, and sodium-rich rocks, and the lower crust of magnesium-rich rocks.
Significance of the findings:
1.While the composition of lunar topsoil near the equatorial and mid-latitude regions have previously been studied by earlier Moon missions sent by other countries, this is the first time that such measurements have been carried out near the Moon’s poles.
2.This makes Chandrayaan 3 the first to carry out in situ experiments of any kind at the poles.
3.The rover moved within a 50-metre radius of the landing site, and took readings on different kinds of surfaces, from relatively smooth ones to near the rims of small craters.
4.The overall finding, which suggests that the topsoil near the landing site is fairly uniform, is novel.
5.The uniformity of the surface is unlike that of Earth, where tectonic plate movements led to the creation of undulating surfaces.
6.With measurements taken at 23 spots along the rover’s path, this is the first time that soil measurements on lunar highlands (light coloured, elevated basins on the Moon standing above dark-coloured basins known as maria) have been taken with such high frequency.
7.Other missions — such as the US’s Apollo 16, Russia’s Luna 20, and China’s Chang’e 4 — too have sampled the lunar highlands, but sparsely.
8. The total observation duration for the APXS measurements was about 31 hours, which were spread out over the mission period of 10 days.
Additional Information:
What are magma oceans?
According to the National Aeronautics and Space Administration (Nasa), magma oceans cover the surface of a celestial body when the formation of a terrestrial planet and some lunar formation takes place.
Scientists believe that the moon was formed when two protoplanets or developing planets collided. Resultantly, the smaller protoplanet, known as Moon, came into existence which was so hot that its entire mantle was molten magma or a magma ocean.