Water on Mars has a different isotopic composition and chemical makeup compared to Earth water
the verdict
SUPPORTED
the evidence backs this
confidence 82/100
Scientific observations and models confirm that water on Mars exhibits distinct isotopic compositions—specifically elevated deuterium-to-hydrogen (D/H) ratios resulting from planetary atmospheric escape and surface-regolith interactions—differentiating it from Earth water.
Evidence for · 3
Predicted diurnal variation of the deuterium to hydrogen ratio in water at the surface of Mars caused by mass exchange with the regolith
2019 · cited by 11
Paper [3] models the isotopic composition (D/H ratio) of water on Mars and its diurnal variation driven by exchange with the regolith.
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More for · 2
Martian atmospheric hydrogen and deuterium: Seasonal changes and paradigm for escape to space
2024 · cited by 10
Paper [4] details how hydrogen and deuterium escape into space, leading to an elevated and changing residual D/H ratio distinct from Earth's water baseline.
The value of returning a sample of the Martian atmosphere.
2025 · cited by 2
Paper [9] highlights the ongoing need to measure elemental and isotopic abundances of Martian volatiles and hydrogen-oxygen species to better constrain their differences from Earth.