GRAIL mission

Source: TOI

Context: A new NASA study using data from the GRAIL mission has revealed why the Moon’s nearside and farside look so different, solving a decades-old lunar mystery.

About GRAIL mission:

• What is GRAIL?

• GRAIL (Gravity Recovery and Interior Laboratory) was a NASA lunar science mission aimed at mapping the Moon’s gravitational field in high resolution.

• Launch Year: Launched in 2011 using a Delta II rocket from Cape Canaveral.

• Organizations Involved: Conducted by NASA’s Jet Propulsion Laboratory (JPL) in collaboration with MIT for scientific oversight.

• Key Features:

• Consisted of two spacecraft, named Ebb and Flow, flying in tandem around the Moon. Measured minute variations in gravitational pull to reveal the Moon’s internal composition. Ended with a controlled impact on the lunar surface after successful mission completion.

• Consisted of two spacecraft, named Ebb and Flow, flying in tandem around the Moon.

• Measured minute variations in gravitational pull to reveal the Moon’s internal composition.

• Ended with a controlled impact on the lunar surface after successful mission completion.

Key Discoveries from GRAIL:

• Tidal Deformation & Gravitational Asymmetry: The Moon’s nearside flexes more than the far side due to Earth’s gravitational pull, indicating asymmetry in internal structure.

• Volcanic History & Heat Distribution: The nearside was more volcanically active, with dark basaltic plains (“known as mare”). Higher concentrations of heat-producing elements like thorium and titanium warmed the nearside mantle up to 200°C more than the farside.

• The nearside was more volcanically active, with dark basaltic plains (“known as mare”).

• Higher concentrations of heat-producing elements like thorium and titanium warmed the nearside mantle up to 200°C more than the farside.

• Crustal Thickness Variation: Nearside crust is thinner, allowing magma to erupt more easily, forming flat plains. Far side remains rugged and cratered due to thicker crust and less volcanic activity.

• Nearside crust is thinner, allowing magma to erupt more easily, forming flat plains.

• Far side remains rugged and cratered due to thicker crust and less volcanic activity.