Rosetta and Philae say comet isn't magnetized

VIENNA, April 14 (UPI) -- Data collected by the European Space Agency's Rosetta probe -- and its lander, Philae, as it thrice bounced off the surface of the comet 67P before landing -- proves the giant ball of ice is not magnetized.

Scientists have long been curious about the role magnetic fields played in the formation of materials during the solar system's earliest days. Now, comet 67P/Churyumov-Gerasimenko may offer answers.

That the comet is unmagnetized suggests magnetic fields failed to influence material formation once objects such as comets, asteroids and planetesimals reached a certain size.

A portion of the material floating about the young solar system contained iron, and some of it became magnetite. It's likely, as material in the protoplanetary disk remained small, magnetic fields could have manipulated small accreting clumps. But as larger formations gathered, gravity likely became the predominant manipulating force.

Scientists had theorized that as magnetized and unmagnetized clumps merged, larger objects could have remained magnetized. But comet 67P suggests not.

Researchers were able to confirm the comet's unmagnetized status by comparing the lander's magnetic readings at different points as it bounced off the comet's surface.

"The unplanned flight across the surface actually meant we could collect precise magnetic field measurements with Philae at the four points we made contact with, and at a range of heights above the surface," Hans-Ulrich Auster, scientist on the Philae lander team, said in a press release.

Auster is the lead author of a paper on the new results, published recently in the journal Science. He and his team presented their findings this week at the European Geosciences Union General Assembly in Vienna, Austria.

Philae's magnetometer reading showed changes in the magnetic field were not based on height, suggesting the comet's nucleus is not magnetized.

"If the surface was magnetized, we would have expected to see a clear increase in the magnetic field readings as we got closer and closer to the surface," explained Hans-Ulrich. "But this was not the case at any of the locations we visited, so we conclude that Comet 67P/Churyumov-Gerasimenko is a remarkably non-magnetic object."

Philae's measurements -- that suggest an unmagnetized comet -- align with readings recorded by Rosetta as it has circled the comet over the last several months.