Solar wind may explain Mercury's weak magnetic field
22.05.12
The mystery of why Mercury's magnetic field is so weak may just have been solved: It is being stifled by the solar wind, researchers think.
Mercury and Earth are the only rocky planets in the solar system to possess global magnetic fields, and for years scientists have puzzled over why Mercury's is so flimsy. Roiling molten iron cores generate magnetic fields, and given how extraordinarily iron-rich Mercury is for its size — its metallic heart may comprise two-thirds of Mercury's mass, twice the ratio for Earth, Venus or Mars — the innermost planet should have a magnetic field 30 times stronger than what spacecraft such as NASA's MESSENGER probe have detected so far.
To study Mercury's magnetic field, researchers created 3-D computer simulations of the planet's interior and of the solar wind , the deluge of energetic particles from the sun that constantly bombards its nearest planet.
The computer models suggested that the churning of Mercury's molten iron core ordinarily would amplify the magnetic field up to Earth-like levels, in a so-called dynamo process like the one within our planet.
Source: msnbc.com