GRAIL Mission

News: A new NASA study, using data from the GRAIL mission, has revealed major differences between the two sides of the Moon. The nearside, visible from Earth, is hotter and more geologically active than the farside. This finding could explain the Moon’s uneven surface. GRAIL Mission.

About GRAIL Mission

GRAIL (Gravity Recovery and Interior Laboratory) was a NASA mission launched in 2011 under the Discovery Program. It aimed to create a high-resolution map of the Moon’s gravity to study its internal structure.

GRAIL Features

1. Twin Spacecraft: GRAIL used two identical spacecraft, Ebb and Flow, flying in tandem to detect small changes in the Moon’s gravity.
2. Gravity Mapping: These measurements created the most detailed gravitational map of the Moon, revealing its deep interior.
3. Launch and Management: Launched in 2011 on a Delta II rocket, it was managed by NASA’s JPL with MIT’s support.
4. Mission End: The mission concluded with a planned impact on the lunar surface.
5. Navigation Use: Data supports future lunar GPS and landing systems.

Key Findings of GRAIL 

1. Interior Differences: The Moon’s nearside is geologically more active and about 100–200°C hotter than the farside.
2. Surface Features: The nearside has large, flat volcanic plains (called mare), while the farside is rugged and mountainous.
3. Volcanic History: Ancient volcanic activity led to the buildup of radioactive elements like thorium and titanium on the nearside. These elements produce heat as they decay.
4. Tidal Deformation: Earth’s gravity pulls more on the nearside, causing it to flex more. This revealed asymmetry in the Moon’s internal structure.
5. Crustal Variation: The nearside crust is thinner, allowing magma to rise easily, while the farside’s thicker crust prevented similar activity.