Why in News
NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission has uncovered key structural and thermal contrasts between the near side and far side of the Moon, explaining its asymmetrical appearance and volcanic history.
About GRAIL Mission
| Aspect | Details |
|---|---|
| Mission Name | Gravity Recovery and Interior Laboratory (GRAIL) |
| Conducted By | NASA (launched in 2011) |
| Spacecraft Names | Twin spacecraft: Ebb and Flow |
| Objective | Map lunar gravity variations to understand Moon’s internal structure |
| Technique | Measured changes in the distance between twin orbiters due to gravity |
| Outcome | Produced highest-resolution gravity map of the Moon |
Key Findings of GRAIL Mission
| Parameter | Near Side (Facing Earth) | Far Side (Hidden from Earth) |
|---|---|---|
| Tidal Locking | Always visible from Earth due to synchronous rotation | Permanently turned away from Earth |
| Crust Thickness | Thinner and more porous | Thicker, which restricts volcanic activity |
| Temperature | Warmer (100–200°C higher) | Colder |
| Volcanic Features | Dominated by dark lava plains (maria) | Fewer lava flows; heavily cratered |
| Surface Texture | Smoother due to ancient molten activity | Bright, rugged, heavily cratered |
| Thermal Asymmetry | Supported by differences in historical internal heating | Inhibited by thick crust and limited magma flow |
Significance of the Findings
| Dimension | Insights Gained |
|---|---|
| Geological | Validates theories of asymmetric volcanic history |
| Structural | Confirms Moon’s porous and thinner crust |
| Evolutionary | Explains the Moon’s Janus-faced appearance (smooth vs cratered) |
| Planetary Science | Enhances understanding of tidally locked celestial bodies |
Implications for India
| Dimension | Relevance |
|---|---|
| ISRO Missions | Offers comparative data for Chandrayaan missions |
| Lunar Research | Aids in identifying potential landing zones based on crust and heat maps |
| Science Education | Enhances curriculum with real-world planetary science applications |
