Produced by: Manoj Kumar
New research reveals Comet 67P’s water shares a molecular signature with Earth’s, reigniting theories that comets may have delivered water to our planet billions of years ago.
In 2014, ESA’s Rosetta mission shocked scientists when it detected three times more deuterium in 67P’s water than Earth’s oceans, casting doubt on comets’ role in water delivery.
The deuterium-to-hydrogen ratio (D/H) serves as a cosmic fingerprint. High levels of deuterium, often in colder regions, link objects like comets to their distant, icy origins.
Led by NASA’s Kathleen Mandt, a new analysis using advanced computational techniques examined 16,000 water measurements from Rosetta’s data, providing clearer insights.
Mandt’s team discovered that dust surrounding 67P skewed deuterium readings. Water attached to dust grains created false signals, inflating the comet’s deuterium levels near the spacecraft.
By analyzing water 75 miles from the comet, where dust effects fade, researchers confirmed 67P’s deuterium levels are closer to Earth’s water, shifting earlier conclusions.
This discovery strengthens the theory that Jupiter-family comets, like 67P, could have delivered water to early Earth during the late heavy bombardment period.
The study not only refines comet measurements but sheds light on the processes in the early solar system, offering clues about planetary formation and water distribution.
Mandt highlights the need to account for dust effects in future comet missions. Revisiting past data could reveal more about comets’ role in shaping Earth’s water supply.