FILE - It’s small, it’s hot, and it’s shrinking. Surprising new NASA-funded research suggests that Mercury is contracting even today, joining Earth as a tectonically active planet. NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State Un …
Mercury is shrinking.
Yes, our solar system sibling is getting smaller, and faster than scientists originally predicted.
Mercury is shrinking
Dig deeper:
Scientists compared Mercury’s shrinkage to a grape shriveling into a raisin under the sun.
By the numbers:
Scientists from the German Aerospace Center’s Institute of Space Research reported Thursday that Mercury’s shrinkage may be 30% greater than previously believed — a loss in diameter of as much as 14 miles (23 kilometers).
That’s significant for a planet barely 3,000 miles (4,900 kilometers) across.
Mercury’s rough surface, continually reshaped by debris hurled from impact craters, may have hidden the true extent of the loss, according to the researchers whose findings appear in the journal Geophysical Research Letters.
The shrinkage could be even more than his team is estimating based on measurements from NASA’s Messenger spacecraft in the 2010s. Only one other spacecraft has ever visited Mercury, NASA’s Mariner 10 in the 1970s.
What's next:
BepiColombo, the spacecraft headed toward Mercury right now, is expected to begin orbiting the planet in November.
BepiColombo should confirm how much Mercury has shrunk so far.
Mercury’s shrinking history
The backstory:
Our solar system’s smallest and innermost planet has been shrinking ever since its formation 4.5 billion years ago.
Its hot iron core — oversized for such a small world — cools and contracts along with the mantle and crust, tightening the surface like a girdle to fit its new slimmer self.
The Source: Information for this article was taken from The Associated Press, NASA and the European Space Agency website. This story was reported from San Jose.