Planet Mercury is shrinking.
Mercury, the planet in our solar system closest to the sun, has lost more than 4 miles of elevation in some areas, according to multiple reports citing new data from NASA's Messenger spacecraft.
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Signs of Mercury’s contraction are noticeable because of
distortions of the planet's surface, according to findings published in the journal Nature Geoscience.
The discovery solved a mystery regarding the evolution of the planet's interior and helped scientists find long-term changes that affect planets without Earth-like plate tectonics.
"Our findings provide a key constraint for studies of Mercury's thermal history," wrote one of the study's authors, Paul Byrne of the Carnegie Institution of Washington, in the journal report.
Mercury's crust is formed by one shell, as opposed to multiple plates that shift, like on Earth. The planet's molten iron core has cooled over billions of years since it formed, causing the surrounding rock shell to
crack and shift to adjust to the smaller size, Discovery News said. Those changes are visible to scientists.
"Some of these things are really, really big," Byrne told Discovery News. "There are some truly gargantuan cliffs on Mercury."
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