{"id":7064534,"date":"2026-09-23T05:50:50","date_gmt":"2026-09-23T05:50:50","guid":{"rendered":"https:\/\/peraltafinancing.com\/aerospace\/mercury-has-wrinkles-that-show-its-shrinking-now-scientists-say-the-planet-has-shriveled-far-more-than-previously-thought\/"},"modified":"2026-09-23T05:50:50","modified_gmt":"2026-09-23T05:50:50","slug":"mercury-has-wrinkles-that-show-its-shrinking-now-scientists-say-the-planet-has-shriveled-far-more-than-previously-thought","status":"publish","type":"post","link":"https:\/\/fivemor.com\/?p=7064534","title":{"rendered":"Mercury Has Wrinkles That Show It’s Shrinking. Now, Scientists Say the Planet Has Shriveled Far More Than Previously Thought"},"content":{"rendered":"


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A new study suggests that our solar system\u2019s smallest planet has shrunk by up to 30 percent since its birth roughly 4.5 billion years ago<\/h2>\n
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Sara Hashemi<\/a><\/p>\n

| Daily Correspondent<\/span><\/p>\n

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Mercury as seen\u00a0by NASA\u2019s MESSENGER spacecraft during a flyby in 2008, before it began orbiting the planet.
\n NASA \/ JHU APL \/ Carnegie Institution of Washington<\/span>
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Mercury, our solar system\u2019s smallest planet and the one closest to the sun, is covered in wrinkles. They tell scientists that the teensy world has shrunk as it cooled over the past 4.5 billion years. Its birthplace was piping hot<\/a>, after all.<\/p>\n

But Mercury may have shriveled even more than previously thought, at around 10 to 30 percent, researchers report in a study published the journal Geophysical Research Letters<\/em><\/a> <\/em>on September 10. That\u2019s a loss of up to 14.5 miles in width\u2014far more than past estimates of around 2.5 to 10 miles\u2014a fairly significant chunk, considering the planet\u2019s current diameter of merely\u00a03,032 miles<\/a>. The findings could unlock new insights about Mercury\u2019s interior and evolution, in turn shedding light on other rocky worlds.<\/p>\n

\u201cThere are lessons about the formation and evolution of large, rocky bodies like our Earth, that can be learned on Mercury better than anywhere else in our solar system,\u201d says Hannes Bernhardt<\/a>, a planetary geologist at the University of Maryland, College Park who wasn\u2019t involved in the study, to Ashley Strickland at CNN<\/a>.<\/p>\n

Mercury is a difficult planet to study.<\/a> Its proximity to the sun makes it tough for a spacecraft to reach; one trying to enter Mercury\u2019s orbit must constantly brake to fight the gravitational pull of our star, and the planet\u2019s surface temperatures are too hot to allow spacecraft to get very close. It\u2019s also hard to observe from Earth, given the brightness of the sun. Only one spacecraft has entered this little world\u2019s orbit: The one used in NASA\u2019s MESSENGER mission<\/a>, which circled Mercury from 2011 to 2015.<\/p>\n

In the new study, researchers combined MESSENGER data with a digital model of Mercury\u2019s\u00a0terrain based on images to create a map of the planet\u2019s surface roughness. They found that rougher areas on Mercury had fewer visible wrinkles\u2014signs of the planet\u2019s contraction\u2014which led them to believe something was obstructing their view of the folds. Perhaps rocky debris kicked up from impacts covered up the ridges formed by shrinkage.<\/p>\n

\u201cThe reason why the estimation remains difficult is that we have to rely on topographies that are visible on the surface of the planet,\u201d says study co-author Gaku Nishiyama<\/a>, a planetary scientist at the German Aerospace Center\u2019s Institute of Space Research, to K.R. Callaway at the New York Times<\/em><\/a>.<\/p>\n

Accounting for those obstructed areas helped the team to calculate the new shrinkage estimate. Up to \u201c30 percent is a little bit surprising, but the corrected amount of contraction actually makes sense to me,\u201d Nishiyama says in a statement<\/a>. The updated numbers allow observations of Mercury\u2019s cooling and shriveling to align more closely with physics-based predictions.<\/p>\n

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Quick fact: Moonless Mercury<\/p>\n

Mercury is one of two solar system planets that lack a moon<\/a>. The other one, Venus, may have had a lunar companion long ago\u2014which the planet ate<\/a>, a recent study suggests.<\/p>\n<\/p><\/div>\n<\/div>\n

\u201cThe authors have thought about an additional angle to figuring out Mercury\u2019s geological history from afar, which is the effect of surface roughness from billions of years of impact bombardment,\u201d says Paul Byrne<\/a>, a planetary scientist at Washington University in St. Louis who wasn\u2019t involved in the study, to Mary Randolph at Scientific American<\/em><\/a>. \u201cIf their results hold\u2014and I\u2019m confident they will\u2014then we\u2019ll have taken a step further in investigating planets we can\u2019t yet visit in person.\u201d<\/p>\n

Understanding Mercury\u2019s shrinkage opens the door to more insights about the mysterious planet. \u201cEvery planet is an odd little duck that has a story to tell,\u201d says Sam Birch<\/a>, a planetary geoscientist at Brown University who also wasn\u2019t involved in the work, to the Times<\/em>. \u201cIf you can understand how fast Mercury is shrinking, you can understand how fast it\u2019s cooling, what size it started at and what it\u2019s made out of.\u201d<\/p>\n

The updated amount of contraction already hints that Mercury might have a larger metal core, with fewer light elements such as silicon mixed in or a higher starting temperature than previously thought, Nishiyama says in the statement. Additionally, he thinks the new numbers could still be an underestimate.<\/p>\n

Thankfully, more data should be coming soon. The European Space Agency and Japan Aerospace Exploration Agency\u2019s BepiColombo mission<\/a> is slated to enter Mercury\u2019s orbit later this year<\/a> and begin scientific operations in April 2027.<\/p>\n

\u201cNew data from BepiColombo will open a door for understanding how Mercury has been shaped up to now,\u201d Nishiyama tells Jeffrey Kluger at Time<\/em><\/a>.<\/p>\n

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