Water-bearing comets and/or asteroids are not the reason behind the water on Moon, a new study has shown suggesting that water was present on Earth’s natural satellite ever since it was formed.
Sitting in line with European Space Agency’s Rosetta mission that proved that comets might not have the source of water on Earth, the new study published in Nature Geoscience pegs water as being present on Earth and Moon right from day one of their formation.
Scientists at Vrije University in Amsterdam including Wim van Westrenen developed a mixture in their lab containing oxygen and silica along with other ingredients including magnesium, calcium, iron, titanium and aluminium. Researchers say that this mixture resembled the moon’s composition and using this they carried out experiments in lab to mimic the components that gave rise to the lunar magma ocean, the initial liquefied mass that gradually cooled and solidified to form the moon.
Scientists came up with the recipe based on the seismic data collected from the moon’s surface by instruments left there by Apollo astronauts. The team then went about simulating the conditions on moon as it would have been while it was evolving by subjecting the mixture to various temperature and pressure conditions. What they specifically did was to subject the mixture both with and without water to see whether this affected the type and amount of rocks formed.
What the team found was surprising. When water was included in the mix, at levels of just 0.5 to 1 per cent by weight, the end result was formation of compounds that reflect the rock composition that has been detected or measured on the moon. Most importantly, the water-based mixture generated a layer of plagioclase—the dominant component of the crust – that when extrapolated to the moon would be around 34 to 43 kilometres thick. This tallies with the average thickness reported in 2013 based on data from satellites orbiting the moon.
In absence of water, the plagioclase layer ended up twice as deep, at 68 kilometres suggesting that the existing make-up of the moon’s geology could only have evolved if water was there at the outset.