Mars' magnetic tail is shaped and twisted by the solar wind.
Magnetic fields around planets are a shielding buffer between the surface and the stream of charged particles that emanate from the Sun and bathe the solar system. Earth's magnetic field surrounds the whole planet, but Mars lost its global magnetic field billions of years ago and what remains is a patchwork of smaller remnant magnetic fields embedded in certain regions of its surface. On the dark side of the planet, these fields stream into a magnetic tail – with a twist. NASA’s Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft has observed Mars' magnetic tail that is shaped by the solar wind. As it flows past Mars carrying its own magnetic fields, the solar wind interacts with the magnetic fields on the Martian surface and causes a phenomenon called magnetic reconnection, which puts a 45-degree twist in Mars' magnetic tail. Researchers believe this same process may also slowly strip away Mars' atmosphere. Like a stretched rubber band suddenly snapping to a new shape, magnetic reconnection releases energy, which could actively propel ions in the Martian atmosphere down the magnetotail into space. Explore the images to learn more.