Results from Europe’s Rosetta mission, which made history by landing on Comet 67P in November, shows the water on the icy mass is unlike that on our planet.
The results are published in the journal Science.
The authors conclude it is more likely that the water came from asteroids, but other scientists say more data is needed before comets can be ruled out.
Here’s the abstract:
The provenance of water and organic compounds on the Earth and other terrestrial planets has been discussed for a long time without reaching a consensus. One of the best means to distinguish between different scenarios is by determining the D/H ratios in the reservoirs for comets and the Earth’s oceans. Here we report the direct in situ measurement of the D/H ratio in the Jupiter family comet 67P/Churyumov-Gerasimenko by the ROSINA mass spectrometer aboard ESA’s Rosetta spacecraft, which is found to be (5.3 ± 0.7) × 10-4, that is, ~3 times the terrestrial value. Previous cometary measurements and our new finding suggest a wide range of D/H ratios in the water within Jupiter family objects and preclude the idea that this reservoir is solely composed of Earth ocean-like water. (paywall)
See also:
“Behold, countless Earths sail the galaxies … that is, if you would only believe …”
The Science Fictions series at your fingertips (origin of life)
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