A new NASA study has found that the inside of the Moon is not the same on both sides, and this could explain why the side facing Earth looks so different from the one we never see.
The findings come from NASA’s GRAIL (Gravity Recovery and Interior Laboratory) mission. Using two robotic spacecraft, GRAIL created the most detailed map of the Moon’s gravity so far. This helped scientists look deep inside the Moon and learn more about how it formed.
They found that the Moon's “nearside”, the side we always see from Earth, is warmer and more geologically active deep down than the far side. This is likely because of massive volcanic activity billions of years ago that shaped the Moon’s surface.
How are the two sides different?
The nearside of the Moon has large dark plains called “mare” made of cooled volcanic rock. The far side is much more rugged and mountainous. Scientists have long wondered why the two sides are so different.
A new study, cited by Reuters, suggests that intense volcanic activity caused certain radioactive elements to accumulate on the Moon’s nearside. These elements, such as thorium and titanium, generate heat as they decay, making the nearside mantle, a deep layer beneath the surface, approximately 100 to 200°C hotter than the farside.
The Moon’s deep interior holds clues
The Moon’s mantle, which lies between the crust and the core, makes up about 80% of its mass. It contains minerals like olivine and pyroxene, which are also found in Earth’s mantle. The scientists noticed that the shape and behaviour of the Moon during its orbit, known as tidal deformation, is also different on each side. This is because Earth’s gravity pulls more on the side facing us.
“The fact that the shape of the mantle matches the surface differences gives us strong evidence that ancient volcanic activity on the nearside shaped what we see today,” said NASA researcher Ryan Park.
Why does this matter?
The improved gravity map of the Moon will help future space missions. It will help in building accurate lunar navigation systems, like GPS on the Moon, which are essential for upcoming lunar exploration.
The same method of studying a planet or moon’s gravity to learn about its inside could also help with studying other moons like Enceladus (around Saturn) and Ganymede (around Jupiter), which are being explored for signs of life.
“The Moon helps keep Earth’s rotation stable and causes ocean tides,” Park said. “Even though we’ve sent many missions to the Moon, there’s still a lot we don’t know about its deep interior and past.”
Inputs from Reuters
The findings come from NASA’s GRAIL (Gravity Recovery and Interior Laboratory) mission. Using two robotic spacecraft, GRAIL created the most detailed map of the Moon’s gravity so far. This helped scientists look deep inside the Moon and learn more about how it formed.
They found that the Moon's “nearside”, the side we always see from Earth, is warmer and more geologically active deep down than the far side. This is likely because of massive volcanic activity billions of years ago that shaped the Moon’s surface.
How are the two sides different?
The nearside of the Moon has large dark plains called “mare” made of cooled volcanic rock. The far side is much more rugged and mountainous. Scientists have long wondered why the two sides are so different.A new study, cited by Reuters, suggests that intense volcanic activity caused certain radioactive elements to accumulate on the Moon’s nearside. These elements, such as thorium and titanium, generate heat as they decay, making the nearside mantle, a deep layer beneath the surface, approximately 100 to 200°C hotter than the farside.
The Moon’s deep interior holds clues
The Moon’s mantle, which lies between the crust and the core, makes up about 80% of its mass. It contains minerals like olivine and pyroxene, which are also found in Earth’s mantle. The scientists noticed that the shape and behaviour of the Moon during its orbit, known as tidal deformation, is also different on each side. This is because Earth’s gravity pulls more on the side facing us.“The fact that the shape of the mantle matches the surface differences gives us strong evidence that ancient volcanic activity on the nearside shaped what we see today,” said NASA researcher Ryan Park.
Why does this matter?
The improved gravity map of the Moon will help future space missions. It will help in building accurate lunar navigation systems, like GPS on the Moon, which are essential for upcoming lunar exploration.The same method of studying a planet or moon’s gravity to learn about its inside could also help with studying other moons like Enceladus (around Saturn) and Ganymede (around Jupiter), which are being explored for signs of life.
“The Moon helps keep Earth’s rotation stable and causes ocean tides,” Park said. “Even though we’ve sent many missions to the Moon, there’s still a lot we don’t know about its deep interior and past.”
Inputs from Reuters
