Mercury has been hiding an exciting secret: the closest planet to our Sun is perpetually shrinking, according to new data from NASA, which shows the appearance of new, tiny cracks on Mercury’s surface called “fault scarps”. This means that out of all the planets in our solar system, only Mercury and the Earth are tectonically active, with crusts that change their shapes from the inside out.
By Madison Margolin | MOTHERBOARD
The findings come from images collected by NASA’s MESSENGER (MErcury Surface, Space ENvironment, GEochemistry and Ranging) spacecraft, and are scheduled to be published in the October issue of Nature Geoscience. The uncrewed MESSENGER orbited Mercury at an extremely low-altitude for part of its mission, allowing it to capture details of the planet’s surface from closer than ever before. The images were obtained in the last 18 months of the MESSENGER’s orbit, before the spacecraft crashed on Mercury on April 30, 2015.
„Mercury is not a body where most of the activity has occurred in the distant past,“ lead author and Smithsonian senior scientist Thomas Watters told Motherboard. „These faults are so small, they’ve got to have formed very recently.“ Because Mercury, like Earth, is tectonically active, the planet’s contractions caused the faults to form.