REAL LIFE NEWS: MERCURY IS GEOLOGICALLY ACTIVE
by Hazed
Earth is the only planet to exhibit seismic activity – that’s what we thought. Some of the moons of Jupiter and Saturn do, but Earth is the only actual planet to do so, it was believed.
But we were wrong. It turns out that Mercury is geologically active too. Images taken near the planet’s north pole in the final months of the MESSENGER mission in 2014 and 2015 have just been re-examined and they show numerous tiny fault scarps in the surface. These are offsets in Mercury’s crust that form as the planet’s interior cools and its crust shrinks.
This crustal shrinking means there is tectonic activity on the planet, which could even trigger Mercury-quakes.
Mercury’s surface is covered with enormous rifts and canyons, which show that the planet’s crust contracted way back in the past – billions of years ago.
However, these smaller fault scarps would not survive more than a few million years because Mercury’s surface is constantly bombarded by meteorites. So the discovery of the fault scarps is an indication that the planet may still be seismically active, with continual contraction of the crust.
This intriguing finding opens up many new questions – chiefly, how has such a small planet maintained enough core heat to stay geologically active for 4.5 billion years?
Source: http://gizmodo.com/we-just-found-out-that-mercury-is-geologically-active-1787130511