The Moon was once covered in a boiling ‘magma ocean’ and formed after ancient planet slammed into Earth
Scientists believe a Mars-sized object smashed into Earth, flinging debris into space that later became the Moon
THE moon was once covered in a sea of boiling lava, experts say – and they have uncovered new evidence that lends itself to another theory.
In addition to boasting a “magma ocean,” the Moon was likely formed after an ancient planet smashed into Earth.
The new evidence comes courtesy of Pragyan, a rover sent to comb the Moon’s surface as part of India’s Chandrayaan-3 mission last summer.
The rover was deployed further south than any others before it. Pragyan has since been traveling across the south pole to gather soil samples and collect information about the Moon’s atmosphere.
Thanks to the miraculous little rover, scientists have uncovered clues about the history of Earth’s closest natural satellite.
A paper published last week in details the results of an analysis of soil sample data, which backs theories that the Moon’s surface was molten not long after its formation.
Scientists examined radiation data sent back from the rover’s alpha-particle X-ray spectrometer.
The rover transmitted information about the makeup of the moon’s regolith, a layer of loose rock and dust that rests atop bedrock.
All 23 samples were composed mostly of a white rock called ferroan anorthosite.
Sensor data from other projects has detected the same material in areas including the equator and mid-latitude zones. The researchers take this as evidence of a uniform layer of material covering the celestial body.
This also gives weight to theories that the moon’s entire surface was covered by bubbling magma soon after its formation.
The same theory proposes that the Moon was formed when a Mars-sized object slammed into the Earth, launching debris into space. The material came together to form the Moon.
As the impact would have generated a considerable amount, this would explain the so-called “magma ocean.”
The theory also explains why many moon rocks have a similar makeup to those on Earth.
Scientists believe the magma ocean existed for hundreds of millions of years but later cooled and crystallized, forming ferroan anorthosite.
The theory was devised after samples returned from the Apollo 11 mission in 1969.
While the soil was mostly composed of dark basaltic rock – similar to the material produced by volcanoes on Earth – it also contained fragments of what was later dubbed ferroan anorthosite.
Researchers hypothesized that the white rock represented tiny fragments of the ancient crust.
As the magma cooled, denser minerals sank to form a deeper layer called the mantle. Ferroan anorthosite, being less dense, drifted to the top.
The composition measured in the latest study is not pure ferroan anorthosite. In fact, it contains more magnesium than expected.
The authors believe their measurements may represent a mixture of material from the ancient crust and the underlying rock layer.
These different layers would have churned together during impact cratering, as objects like asteroids and meteorites struck the Moon throughout its history.
The Moon – our closest neighbour explained
Here's what you need to know...
- The Moon is a natural satellite – a space-faring body that orbits a planet
- It’s Earth’s only natural satellite, and is the fifth biggest in the Solar System
- The Moon measures 2,158 miles across, roughly 0.27 times the diameter of Earth
- Temperatures on the Moon vary wildly. Nasa explains: “Temperatures near the Moon’s equator can spike to 250°F (121°C) in daylight, then plummet after nightfall to -208°F (-133°C). In deep craters near the Moon’s poles, permanent shadows keep the surface even colder — NASA’s Lunar Reconnaissance Orbiter has measured temperatures lower than -410°F (-246°C).”
- Experts assumed the Moon was another planet, until Nicolaus Copernicus outlined his theory about our Solar System in 1543
- It was eventually assigned to a “class” after Galileo discovered four moons orbiting Jupiter in 1610
- The Moon is believed to have formed around 4.51billion years ago
- The strength of its gravitational field is about a sixth of Earth’s gravity
- Earth and the Moon have “synchronous rotation”, which means we always see the same side of the Moon – hence the phrase “dark side of the Moon”
- The Moon’s surface is actually dark, but appears bright in the sky due to its reflective ground
- During a solar eclipse, the Moon covers the Sun almost completely. Both objects appear a similar size in the sky because the Sun is both 400 times larger and farther
- The first spacecraft to reach the Moon was in 1959, as part of the Soviet Union’s Lunar program
- The first manned orbital mission was Nasa’s Apollo 8 in 1968
- And the first manned lunar landing was in 1969, as part of the Apollo 11 mission