The planet Mercury, which measures at around 3000 miles in diameter, or less than one 18th the mass and volume of Earth, is slowly getting smaller. Researchers estimate that it has decreased in size by over 4 miles since it first solidified more than 4 billion years ago.
The planet Mercury, which measures at around 3000 miles in diameter, or less than one 18th the mass and volume of Earth, is slowly getting smaller.
Researchers estimate that it has decreased in size by over 4 miles since it first solidified more than 4 billion years ago.
Doctor Dave Rothery from the Open University in the United Kingdom who worked on the study is quoted as saying: “People used to think the Earth was shrinking - which it is a little bit, but we can't see it because of the way tectonic plates are created and destroyed on the Earth.”
But Mercury reportedly only has one tectonic plate, and the liquid core of the planet is slowly cooling and turning into a solid.
This process causes the planet to lose volume and wrinkles the rocky surface, making it slightly smaller.
NASA sent spacecrafts to study Mercury starting in 1974, but less than half of the planet was documented at that time, and another mission didn’t visit there for over 30 years.
The Messenger satellite began its orbit of Mercury in 2011 and has now taken pictures of the entire planet’s surface and collected data from rocks for analysis.