Mercury's core dynamo present early in planet's history
American Association for the Advancement of Science (AAAS)
As Mercury also has a magnetic field in operation today, the evidence for an ancient field suggests that Mercury’s dynamo has persisted for billions of years. On April 30, 2015, the Messenger spacecraft - the first to orbit Mercury - crashed into the enigmatic planet. During the four years it orbited Mercury, Messenger provided vast amounts of data to scientists. Now, using low-altitude satellite observations from the spacecraft, Catherine Johnson et al. report a weak magnetization signal that appears to emanate from an ancient region of Mercury’s crust. Neumann at NASA Goddard Space Flight Center in Greenbelt, MD; B.J.