Researchers of the Rosetta Mission have made a sensational discovery — the comet 67P/Churyumov-Gerasimenko may not have a magnetic field.
This discovery is important because it calls into question some of the theories of formation of structures, such as our solar system, in which magnetic field is crucial to the formation of clumps of matter which later grew to become large celestial bodies.
When the Rosetta mission arrived at its destination, floating in sync with the comet 67P, it dropped a lander, Philae, which contained instruments for measuring various parameters on the comet, including its magnetic field. Philae was supposed to anchor itself, by means of some harpoons, to the surface of the comet on landing. However, this mechanism failed, and it bounced off the surface a couple of times to land some distance away, following a complex path.
This turned out to be scientifically beneficial to the scientists who were looking at the magnetometer measurements from Philae and from the Rosetta spacecraft. They could collect precise magnetic field measurements at the four points where Philae made contact and at a range of heights.
The strength of the magnetic fields measured did not increase systematically as the point of observation moved closer to the comet’s nucleus. This rules out the possibility that the nucleus of the comet carries any magnetism.
Instead, the observed value is consistent with there being an external source of magnetism, namely the solar wind and interplanetary magnetic field near the comet nucleus. These findings of Philae were complemented by measurements made by Rosetta at the same time, thereby adding weight to the conclusions.
These results were published in the recent edition of the journal Science by Hans-Ulrich Auster et al ,. Dr. Auster is the lead author from the Institut für Geophysik und extraterrestrische Physik, Technische Universität Braunschweig, Germany.