Mercury has shrunk significantly more than previously estimated, study finds

The short version

• A study in Geophysical Research Letters estimates Mercury has contracted 10 to 30 percent more than earlier calculations indicated.[Scientific American · ABC News]
• Scientists found that rough terrain, including impact craters and debris, previously obscured many contraction wrinkles across the surface.[Scientific American · ABC News]
• The planet's diameter may have decreased by as much as 23 kilometers, or about 14 miles.[Scientific American · ABC News]
• The upcoming arrival of the BepiColombo spacecraft in November could provide orbital measurements to help confirm the findings.[ABC News]

Key facts

• A study published in Geophysical Research Letters found that Mercury has shrunk 10 to 30 percent more than previously recognized.[Scientific American · ABC News]
• Surface roughness caused by impact debris and craters obscured tectonic wrinkles, masking the full scale of the contraction.[Scientific American · ABC News]
• The updated calculation suggests Mercury may have shrunk by up to 23 kilometers, compared to earlier 2013 estimates of about 11 kilometers.[Scientific American]
• The BepiColombo spacecraft is scheduled to enter orbit around Mercury in November to conduct a comprehensive survey.[ABC News]

Sources

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.

• The planet Mercury is shrinking far faster than we thoughtScientific American metered
• Little Mercury may be shrinking faster than scientists expectedABC News - Technology