Mercury's Magnetic Field Is Way Older Than We Thought
Before NASA's MESSENGER probe crashed into Mercury, readings indicated the planet's magnetic field could be some 400 million years older than Earth's.By Evan Thomas | May 10, 2015
In one of its final acts before plowing into the surface of Mercury at more than 8,700 mph, NASA's MESSENGER mission determined the planet's magnetic field is older than we thought.
MESSENGER only recently got close enough to notice; it captured the readings at just 9 miles above the surface of the planet. Catherine Johnson, planetary scientist and author of a paper on the new findings, explains. (Video via NASA)
She told Space.com: "The signals we detected are really small, and very, very hard to measure. We'd never have been able to measure them if not for these really risky low-altitude observations in the last few months of the MESSENGER mission."