Comets Did Not Bring Water to Earth, New Study Confirms Thanks to Philae Data

One of the main inquiries scientists had when planning the Philae lander's comet touchdown has been answered.

According to BBC News, the ice on Comet 67P is not like the water on Earth, meaning our planet did not get its water from comets. The new discovery was made as Rosetta mission managers were reviewing some of the data Philae beamed back to Earth as its batteries were draining shortly after landing.

A study on the matter is published in the journal Science.

"This ratio between heavy and light water is very characteristic. You cannot easily change it and it stays for a long time," study lead author Kathrin Altwegg, from the University of Bern in Switzerland, told BBC News. "If we compare the water in comets with the water we have on Earth, we can definitely say if the water on Earth is compatible with the water on comets."

The European Space Agency (ESA) became the first organization to land a spacecraft on a comet, but unfortunately the attempt was not as smooth as desired. Philae bounced several times and wound up in a spot where the sun could not charge its solar panels, but mission managers were able to command Philae to gather whatever it could before powering down to idle mode.

"Today asteroids have very limited water, that's clear. But that was probably not always the case," Altwegg told the Guardian.

Right now, Rosetta mission managers will have to wait for Comet 67P to get closer to the sun and expose Philae to its rays. Until then, they will be left with what it could provide before conserving whatever energy it has.

"Once we get the identification of where the lander is, it will give us a better fix on what we believe the illumination conditions are and a better idea of when we would expect the lander to have sufficient illumination to be able to start charging its batteries and come back online," Matt Taylor, a Rosetta project scientist with the ESA, told the Guardian. "We're focusing on what is known as an activity campaign to try and fly directly through a jet and we aim to do that hopefully around summertime next year."