The reananalysis of “rubber-ducky” comet's data, which was collected nearly a decade ago, suggested that comets may have deposited a lot more water on Earth than scientists thought previously. In the past decade, the idea that water was delivered by comets to early Earth has fallen out of favour. However, a new look at data from the European Space Agency's (ESA) Rosetta mission to an iconic “rubber ducky” comet has reopened that possibility, reported . It is important to note that water has a pretty simple chemical makeup. It has just three atoms — two hydrogen and one oxygen — in each molecule. Moreover, with our planet's oceans brimming with about a million trillion tonnes of the liquid, it’s also one of Earth’s most abundant molecules. Though, it has remained a mystery how all of this water ended up on Earth. According to some scientists, although Earth's geological processes may have generated a tiny fraction of it, most water was likely deposited by comets or asteroids via repeated, cataclysmic collisions. Earth's D/H ratio is similar to those of many asteroids and a handful of Jupiter-family comets, as per the research over the past few decades. Additionally, the comets from the Jupiter-family are a group of comets that swing past the sun roughly every 20 years and whose paths are tweaked by Jupiter's gravity.