Comet didn't bring water to Earth, according to early Rosetta results

Early results from Europe’s Rosetta spacecraft challenge the theory that comets delivered water to our planet.

On analysis of water coming from comet 67P on which the European Space Agency made history by landing a probe, it seems Earth’s water molecules contain less hydrogen than those on the comet.

However scientists are not deterred, suggesting that comets originate from different parts of space and some may well have different types of water.