---
title: "Earth’s Water Probably Didn’t Come From Comets, Rosetta Data Suggests"
description: "One of the first major findings from the Rosetta mission has shed light on the origin of Earth’s water - and revealed that it most likely didn't come from comets, as had previously been suggested."
date: "2014-12-11"
modified: "2015-08-13"
authors:
  - name: "Oana Stefanescu"
    link: "https://futurism.com/authors/kidco"
url: "https://futurism.com/earths-water-probably-didnt-come-comets-rosetta-data-suggests"
categories:
  - "Off-World"
  - "Space"
tags:
  - "space"
---

# Earth’s Water Probably Didn’t Come From Comets, Rosetta Data Suggests

![](<https://futurism.com/wp-content/uploads/2014/12/rosetta-67p-comet-esa-complete-640x480.jpg>)

- The Rosetta spacecraft has been analysing the water frozen on Comet 67P and has now discovered that its isotope ratio is significantly different to the water found on Earth
- In order to work out whether water from a comet is similar to water on Earth, scientists examine the ratio of deuterium - a heavy hydrogen isotope - to regular hydrogen
- Using a technique called mass spectrometry, Rosetta was able to analyse the ratio of the water on Comet 67P, and discovered that its ratio of deuterium to hydrogen is around three times higher than the water on Earth.