Scientists have found that cometary dust affects the interpretation of spacecraft measurements, reopening the case for comets like 67P as potential sources of water for early Earth.
Research has shown that some of Earth’s water originated from asteroids and comets that crashed into our planet. However, the role of comets in delivering this water to Earth was uncertain. Researchers have now found evidence that comets contain a similar molecular signature to the water in Earth’s oceans, contradicting previous results.
The discovery was made by analyzing data from NASA’s Rosetta mission to Comet 67P/Churyumov–Gerasimenko. Scientists measured the ratio of deuterium (a rare isotope of hydrogen) to regular hydrogen in the comet’s water vapor and found similar levels to those in Earth’s oceans.
However, previous measurements had shown that Jupiter-family comets, like 67P, contained more deuterium than expected. Researchers thought this was due to cometary dust affecting the readings of the hydrogen ratio. Now, scientists have confirmed that cometary dust can indeed alter these measurements, making it difficult to accurately determine the comet’s water composition.
The new findings suggest that comets may have played a major role in delivering water to early Earth, contradicting previous results from the Rosetta mission. The discovery has significant implications for understanding the formation of our solar system and the origin of our planet’s water.
“Mandt’s team found a clear connection between deuterium measurements in the coma of 67P and the amount of dust around the Rosetta spacecraft,” said Kathleen Mandt, planetary scientist at NASA’s Goddard Space Flight Center. “This means there is a great opportunity to revisit our past observations and prepare for future ones so we can better account for the dust effects.”
The study’s authors hope that their findings will help scientists better understand comets’ role in delivering water to early Earth and shed new light on the solar system’s formation.
Source: https://science.nasa.gov/solar-system/comets/nasa-led-team-links-comet-water-to-earths-oceans