Modern Study Reveals Mercury's Ongoing Shrinking Process

Sunday - October 8 2023, 18:21 UTC - 1 year ago

Mercury's shrinkage is attributed to the cooling of its core, and a recent study undertaken by researchers at the United Kingdom's Open University has provided fresh insights into this planetary phenomenon. The analysis of NASA's MESSENGER spacecraft data shows evidence of new geological features, known as "graben" that formed on scarps, suggesting that Mercury's contraction activity occurred around 300 million years ago. The BepiColombo mission currently holds the potential to solve the mystery of Mercury's ongoing shrinking process.

Mercury, our solar system's smallest planet, appears to be getting even smaller. Since NASA's Mariner 10 mission arrived at Mercury in the 1970s, planetary scientists have been aware of the planet's shrinkage. This shrinking is attributed to the cooling of its core. The thermal contraction began some three billion years ago, but it is unknown if it is still happening. A recent study undertaken by researchers at the United Kingdom's Open University has provided fresh insights into this planetary phenomenon .

The latest findings indicate that Mercury experienced relatively recent contraction activity. In geological terms, this activity occurred about 300 million years ago, suggesting that Mercury might still be undergoing shrinkage. Examination of NASA's MESSENGER spacecraft data shows that the planet's outer surface (crust) wrinkles as a result of this contraction or shrinking, forming visible geological features such as cliffs, scarps, and ridges .

These features document scarp surface features caused by the planet's contraction. In this study, scientists examined more recent images captured by NASA's MESSENGER spacecraft. From 2011 through 2015, the orbiter circled Mercury, documenting surface-based tectonic features in great detail. Through an analysis of its data and images, the team identified a new geological feature known as "graben" that formed on scarps .

These grabens are tiny cracks seen on particular scarps that indicate the planet's shrinking, with dimensions of less than one kilometer-wide and a depth of some 100 meters or less. "These grabens would occur if a thrust slice of the crust has been bent as it is pushed over the adjacent terrain. If you try to bend a piece of toast, it may crack in a similar way", mentioned the study authors in the Conversation report .

The team estimates that grabens formed roughly around 300 million years ago. The results imply the potential that Mercury's core may not have fully cooled and could still experience further contraction. The BepiColombo mission, a collaboration between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA), holds the potential to unravel more details on graben and perhaps solve the mystery of Mercury's ongoing shrinking process .