Scientists have dealt a blow to the theory that most water on Earth came from comets.
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.
Since August, the Rosetta probe has been orbiting Comet 67P/Churyumov-Gerasimenko, and on 12 November its lander, Philae, made a historic touchdown on the object’s surface.
Although the robot’s batteries ran out soon after setting down, it gathered a wealth of scientific data, and the Rosetta “mothership” continues to analyse the wandering “ice mountain”.
This unprecedented, close-up look at a comet is helping scientists to answer the fundamental question of whether a bombardment of these primitive bodies brought water to Earth billions of years ago.
