Washington, Jan 31 : New information obtained by the NASA Messenger spacecraft has indicated that the magnetosphere of Mercury is more similar to Earth's than previously believed.
The new finding was made with the help of U-M's (University of Michigan) Fast Imaging Plasma Spectrometer (FIPS) aboard the Messenger, which took the first direct measurements of Mercury's magnetosphere to determine how the planet interacts with the space environment and the Sun.
The solar wind, a stream of charged particles, fills the entire solar system. It interacts with all planets, but beats down on Mercury, which is two-thirds closer to the Earth than the Sun.
Though Mercury's magnetic field is weaker in comparison to Earth, it is strong enough to fend off the harsh solar wind from most of the planet's surface.
Because Earth's magnetic field also gives it protection from the solar wind's radiation, this feature makes Mercury's magnetosphere similar to that of our planet.
"From our magnetic measurements, we can tell Mercury is managing to stand up to a lot of the solar wind and protect the surface of the planet, at least in some spots," said Thomas Zurbuchen, FIPS instrument project leader. According to Zurbuchen, scientists can tell Mercury is putting up a good fight because instruments detected a layer of much slower-moving magnetospheric plasma around the planet.
"Mercury's magnetosphere is more similar to Earth's than we might have thought," said Zurbuchen.
Mercury and Earth are the only two terrestrial planets in the solar system with magnetospheres produced by an intrinsic magnetic field.