Study: The Early Moon Contained More Water Than Earth

Today, people see the Moon as just a big lump of mass circling the planet. A new team of scientists in the Netherlands, however, found that the Moon once harbored more water than Earth.

It is hard to imagine that the Moon once contained water because of how it looks now. Many scientists are aware that the satellite formed when another planet hit Earth in a huge collision, throwing out debris that eventually merged into the now called Moon.

Since the collision was huge, the young Moon was hot because of the energy left over from the impact. This means that the Moon had a very hot interior, hot enough for liquid magma to exist inside.

Now, a new study published in the journal Nature Geoscience provided an insight on how much water the Moon had in its rocks when it first formed. It also gave a glimpse of the Earth's composition while the Moon was still young.

Billions of years ago, a primordial body has split apart to become Earth and the Moon. The researchers wanted to see if the early Moon and Earth contained water from the outset, or whether it formed later because of the collusions with water-containing asteroids or comets.

Moon Contained Water Early On

The researchers also analyzed if the early Moon once contained water.

"Our study shows that water was there at the time the moon formed and because that happened soon after the formation of Earth, it shows water was present well before any later addition via comets or asteroids," Wim van Westrenen from the Vrije University in Amsterdam, Netherlands, told the New Scientist.

"We show that the moon, in its initial hot stage, contained a lot of water - at least as much as, and likely more than, the amount we have on Earth today," he added.

Mimicking The Early Moon's Ingredients

To investigate the role of water in the formation of the young Moon, the researchers created a small-scale lab mixtures containing the basic ingredients from which the Moon came from. These ingredients are similar to the components that made the lunar magma ocean.

Containing the main ingredients, silicon and oxygen, and other elements like magnesium, calcium, aluminum, iron and titanium, the researchers subjected the mixture to various temperatures and pressures. They then studied the types of rocks formed from the experiment.

They found that when they added water to the mixture, the rocks that formed matched those that have been found on the Moon.

True enough, adding 3,150 parts per million of water to a 700-kilometer-deep magma ocean produced plagioclase at a slower rate. This reduced the model of the crust's thickness to 42 kilometers, matching NASA's observations, Cosmo Magazine reports.

This means that water must have been present as the magma ocean cooled and crystallized, leading to what the Moon looks like now. Since the Earth and Moon came from the same hot disc, the study suggests that the Earth contained water at the time.