Significant audit over the evolution of sky bearings
In the current ie of the Science Magazine Nature offer Dave R. Stegman, A. Mark Jellinek and Mark Richards of the University of California in Berkeley, Stephen A. Zatman from Washington University as well as John R. Baumgardner from Los Alamos National Laboratory An explanation of how a magnetic field of the moon could have been created a long time ago and later disappeared.
Moon, picture: NASA
The only natural satellite of the earth is still advisable in many aspects. To the unclear questions also lake the lunar magnetic field. Today, the moon has no comprehensive magnetic field, but from the Apollo missions (cf. Today 30 years ago, the last person fell in love with the moon) to the earth, suggested that there was ahead of 3.9 to 3.6 billion years ago.
Magnetic fields give essential audit over the evolution of sky bearings. Planets like the earth or gas giant Jupiter have their own inner dynamos with which they create their magnetic fields and maintain. The terrestrial geodynamo is not completely understood yet, but the geophysics ame that the bottom of the earth works like an over-dimensional natural generator, which means the interaction of flowers in the absorber, liquid metallic core, the coat and the earth rotation by mechanical energy For the generation of a magnetic field (cf. Shell construction of the earth). The electrical conductivity of the molten iron in the moods is high. The electric streams are surrounded by magnetic fields.
The magnetic field generated by the earth dynamo is not uniform and not stable. The main field consists of a symmetrical part, the dipole field, there are in a wide range, so to speak as islands, asymmetric shares, which formulate from corresponding electricity systems. The Earth’s magnetic field is aligned today to Suden, but we are probably back in a phase of upcoming polishing (cf. Polishing in the next millennium). An important role in generating the planetary magnetic field plays convection, D.H. Warm transmission due to the flow of flow or gases that lead to the expansion or compaction of matter.
The group around Stegman has investigated the problem of a lunar geodynamos using a three-dimensional simulation model. So far did not like to explain to the more common models as the moon could have succeeded in keeping his inner dynamo racing several hundreds of millions of years. But Stegman and colleagues served state-of-the-art computer technology, based on the well-known models of the earth magnetic field and referred to the special chemical properties in the mone in their calculations. Dave Stegman said:
This three-dimensional convection model gives an elegant explanation for the magnetic field that discovered astronauts on the moon. If this model is correct, it was the first time that the thermal history of a planet included the earth was completely understood, and the goods have a milestone to understand the history of all planets as well as Mars and Earth.
Model of the moon with the enormous superplume of hot rock (in red), which is up to the surface "gullpst" will. Image: UC Berkeley
The model calculation showed that after its emergence of 4.5 billion years ago, after its origin, by the collision of the Earth with a gigantic meteorite, the moon started slowly began to build with a gigantic meteorite and form layers of different density under its surface. The heavy elements fell into the interior and the lighter formed a thick coat around around. This resulted in a dense layer in which radioactive elements enriched. Due to their density they dropped off, the radioactive decay caused for arming and the moon started the heater matter "eager", That’s how she rose in eruptions to the surface. This did she in a kind of flag or spring shape, which is why researchers describe these formations as superplums. Through this convection, the lunar dynamo was set in motion and operated for a while before he went out. The resulting magnetic field was a tenth of Gauss strong, which corresponds to a five-art fum of earth.
But the model must only be confirmed, especially since the palaomagnetic analyzes are controversial from the moon. The magnetic traces in the rock could also be caused by meteorite information on the moon surface. Nevertheless, Maria T says. Zuber from the with in Massachusetts in your accompanying newsViews Article:
"Although the results of the present study do not constitute real proof of a Fruhen Lunar Dynamo, they demonstrate the theoretical possibility of a dynamo… Further simulations, continued analysis of the palaomagnetic properties of the lunar samples as well as a low-high, global mapping of the magnetic signature of the moon will be required to really understand the complicated nature of lunar magnetism."
That will probably happen soon, because there is a new race for loads on the moon, while the Japanese, the Indians and the Chinese are planning all manned missions (cf. The long march in space).