Mercury Might Still Be Shrinking, New Research Suggests

New research suggests that Mercury, the smallest planet in the solar system, may still be actively shrinking. Scientists have long believed that the planet is contracting over billions of years due to internal cooling, which has caused its crust to form wrinkles known as “scarps.” However, recent studies on the geological features of Mercury, such as the small cuts called “grabens” that occur on the backs of the scarps, indicate that the planet’s shrinking process may still be ongoing. These small cracks, which would have smoothed over if they were as old as the scarps themselves, suggest that Mercury is still experiencing seismic activity.

The MESSENGER probe sent back photos of numerous possible grabens and confirmed grabens on scarps during its orbit around Mercury between 2011 and 2015. The European and Japanese BepiColombo probe mission, launched in 2018, is expected to provide more insight into this phenomenon with higher-resolution photos of the planet. Scientists hope that this mission will confirm whether Mercury is still seismically active and conclusively determine if the planet is continuing to shrink over time.

Source: Mercury Has Wrinkles Because It’s Shrinking, Scientists Say