Quirks & Quarks

MESSENGER Mission and Mercury's Magnetism

The MESSENGER mission during its final days was able to fly low and detect Mercury's "fossil" magnetic field from 3.8 million years ago.

NASA's Mercury mission examines ancient magnetism

A depiction of the MESSENGER spacecraft flying over the colour-enhanced surface of Mercury. (NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington)
NASA's MESSENGER mission to Mercury ended recently and, having run out of fuel, the spacecraft was crashed into the planet.

But in the last months of its life, the probe did exciting and risky close-in orbital flybys of Mercury, approaching as close as 25km to the surface of the planet. In doing so, it was able to read the magnetic field embedded in surface rock on Mercury that formed nearly four billion years ago.

According to Dr. Catherine Johnson, a geoscientist in the Department of Earth and Ocean Sciences at the University of British Columbia, and a Senior Scientist with the Planetary Science Institute in Tucson, Arizona, this fly-by allowed her and her colleagues to conclude that Mercury's magnetic field has likely existed for most of the lifetime of the planet.

Related Links

- Paper in Science
Science news story
- University of British Columbia release
- MESSENGER mission