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Asteroid Ryugu Unveils Surprising Origins of Earth's Water

9/10/2025

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Summary

Story summary

Asteroid Ryugu reveals that liquid water existed longer than previously believed.
Its parent asteroid contained 20-30% water, indicating that asteroids delivered water as ice rather than just minerals.
Ryugu's formation involved a collision that melted buried ice, enabling water flow.
Chemical analysis shows a unique lutetium-176 to hafnium-176 ratio, suggesting late fluid flow.
These findings challenge prior assumptions about Earth's water origins and highlight the value of sample return missions.

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Story summary

Asteroid Ryugu reveals that liquid water existed longer than previously believed.
Its parent asteroid contained 20-30% water, indicating that asteroids delivered water as ice rather than just minerals.
Ryugu's formation involved a collision that melted buried ice, enabling water flow.
Chemical analysis shows a unique lutetium-176 to hafnium-176 ratio, suggesting late fluid flow.
These findings challenge prior assumptions about Earth's water origins and highlight the value of sample return missions.