• Email Us: [email protected]
  • Contact Us: +1 718 874 1545
  • Skip to main content
  • Skip to primary sidebar

Medical Market Report

  • Home
  • All Reports
  • About Us
  • Contact Us

The Moon Is Shrinking, Mercury Is Shrinking. Is The Earth?

January 21, 2025 by Deborah Bloomfield

When observing the various objects in our Solar System and beyond, scientists have found evidence that some of them appear to be shrinking. So what is going on, and is this happening to the Earth?

Mercury is shrinking

ADVERTISEMENT GO AD FREE

Back in 1974, NASA’s Mariner 10 mission flew by Mercury and discovered evidence that it, already the smallest planet in the Solar System, is shrinking. This evidence came in the form of kilometers-high slopes known as “scarps” all across the planet. These are caused by faults beneath the scarps called “thrusts” as the planet contracts due to thermal cooling.

“Because Mercury’s interior is shrinking, its surface (crust) has progressively less area to cover. It responds to this by developing ‘thrust faults’ – where one tract of terrain gets pushed over the adjacent terrain,” David Rothery, Professor of Planetary Geosciences at the Open University and author of a 2023 paper exploring the planet’s contraction, explained in a piece for The Conversation. “This is like the wrinkles that form on an apple as it ages, except that an apple shrinks because it is drying out whereas Mercury shrinks because of thermal contraction of its interior.”

A diagram of a thrust fault on Mercury causing shortened craters.

Shortened craters are a sign of the planet’s contraction.

In 2014 it was estimated that the planet had contracted around 7 kilometers (4.4 miles). On Mercury, we can get a pretty good idea of when this shrinking happened by looking at the many impact craters that cover its surface. While some of the craters have become shortened by the planet’s contraction (shown in the above diagram), there are also craters on top of scarps, meaning that the impact that caused them happened after the fault shifted the planet’s crust.

From this, astronomers concluded the scarps were mostly around 3 billion years old. In the 2023 study, however, the team found evidence that the planet’s contraction isn’t over yet, as Mercury continues to cool down.

On these scarps, Open University PhD student Ben Man found “grabens”, where land had fallen down in between two faults, and a sign of stretching.

“Stretching may seem surprising on Mercury, where overall the crust is being compressed,” Rothery explained, “but Man realised that these grabens would occur if a thrust slice of crust has been bent as it is pushed over the adjacent terrain. If you try to bend a piece of toast, it may crack in a similar way.”

ADVERTISEMENT GO AD FREE

As these grabens had not been entirely covered by debris from impacts on Mercury, the team was able to estimate that the stretching and collapsing took place less than 300 million years ago, evidence that the contraction of the planet is still taking place today.

The Moon is shrinking

Back in 2010, astronomers looking at the geology of the Moon made the not entirely unexpected discovery that the Moon is also shrinking. Again looking at scarps, this time in images taken from cameras aboard Apollo 15, 16, and 17, the team found that the Moon has been contracting as it cools, and fairly recently to boot.

“One of the remarkable aspects of the lunar scarps is their apparent young age,” Tom Watters, a planetary scientist in the Center for Earth and Planetary Studies at the National Air and Space Museum, said in a statement at the time. “Relatively young, globally distributed thrust faults show recent contraction of the whole Moon, likely due to cooling of the lunar interior. The amount of contraction is estimated to be about 100 meters [328 feet] in the recent past.”



ADVERTISEMENT GO AD FREE

In 2019, analyzing data from a number of seismometers on the Moon by the Apollo program, scientists including Watters found further evidence that the Moon is continuing to get smaller.

“We think it’s very likely that these eight quakes were produced by faults slipping as stress built up when the lunar crust was compressed by global contraction and tidal forces, indicating that the Apollo seismometers recorded the shrinking Moon and the Moon is still tectonically active,” Watters said in a NASA statement.

“Our analysis gives the first evidence that these faults are still active and likely producing moonquakes today as the Moon continues to gradually cool and shrink.”

Is the Earth shrinking?

The Earth is a little more complicated than the Moon and Mercury due to its thicker atmosphere. The Earth does gain a little mass, as around 40,000 tonnes of material – dust and rock – falls to our planet every year. This is negligible, however, compared to the amount of gas lost from our atmosphere to space.

ADVERTISEMENT GO AD FREE

“Physicists have shown that the Earth is losing about three kilograms [6.6 pounds] of hydrogen gas every second. It’s about 95,000 tonnes of hydrogen that the planet is losing every year,” Dr Chris Smith, microbiologist and science communicator, explained to the BBC.

“The other very light gas this is happening to is helium and there is much less of that around, so it’s about 1,600 tonnes a year of helium that we lose.”

Balancing this and other factors, such as the core losing energy as it cools and the planet gaining a little energy due to climate change, Smith estimates that the Earth gets around 50,000 tonnes lighter every year. This sounds dramatic, but is a loss of around 0.000000000000001 percent of the planet’s overall mass. 

Meanwhile, by using a number of techniques including satellite laser ranging with millimeter-level precision, scientists have determined that the Earth’s overall radius changes at about the rate of 0.1 millimeters (0.004 inches) per year, which is about the width of a human hair.

Deborah Bloomfield
Deborah Bloomfield

Related posts:

  1. Audi launches its newest EV, the 2022 Q4 e-tron SUV
  2. Dinosaur Prints Found Under Restaurant Table Confirmed As 100 Million Years Old
  3. Archax: Japanese Engineers Make Transformer Robot That Actually Works
  4. How Do We Know There Is Anything Beyond The Observable Universe?

Source Link: The Moon Is Shrinking, Mercury Is Shrinking. Is The Earth?

Filed Under: News

Primary Sidebar

  • Dangerous Radiation Awaits Astronauts On Mars – New Mission Could Work Out Just How Much
  • A 4.9 Million-Year-Old Ecosystem Of Interconnected Worlds Is Preserved In A Tennessee Sinkhole
  • 100 Years Since The Scopes (Monkey) Trial: How Much Has Changed Since America’s “Trial Of The Century”?
  • Elephants Use All Kinds Of Gestures To Communicate – They Just Want Apples
  • NASA’s Parker Solar Probe Finds Evidence Of “Barrier” In The Sun’s 2 Million Kelvin Atmosphere
  • Watching Videos At Higher Speeds May Save Time But It Has Some Drawbacks
  • In 2008, Ukraine’s Space Agency Sent A Message To Planet Gliese 581c. It Will Arrive In 2029
  • In A First, A Robot Listened To Spoken Instructions And Performed Surgery – Just Like A Human Would
  • Newly Discovered “Bone-Digesting” Cells Help Burmese Pythons Consume Every Last Bit Of Their Prey
  • Gold Can Be Made By Scientists In A Lab – There’s Just One Problem
  • Recovery Of 24-Million-Year-Old Protein Fragments From Extinct Animal Opens “New Chapter” Of Biology
  • 6 Leading Medical Organizations Team Up To Sue RFK Jr Over COVID-19 Vaccine Policy
  • Less Ice, More Fire: Evidence Melting Glaciers Make Volcanic Eruptions More Explosive
  • This Mini Fridge-Sized Spacecraft Could Study A Time Of The Universe We’ve Never Seen Before
  • Psilocybin Shows Potential In Slowing Human Cell Aging And Increasing Lifespan In Mice
  • Blue Sharks’ Freaky Tooth-Skin Makes It Possible For Them To Change Color To Green And Even Gold
  • Summer In The Northern Hemisphere Will Be 15 Minutes Shorter Than Last Year’s
  • Your Ability To Be Funny May Not Be Inherited After All, And That’s Really Unexpected
  • New Interstellar Comet Tracked To Its Origin Region: “It’s Much Older Than The Solar System”
  • ChatGPT Gets “Absolutely Wrecked” By An Atari Video Chess Game Built In 1979
  • Business
  • Health
  • News
  • Science
  • Technology
  • +1 718 874 1545
  • +91 78878 22626
  • [email protected]
Office Address
Prudour Pvt. Ltd. 420 Lexington Avenue Suite 300 New York City, NY 10170.

Powered by Prudour Network

Copyrights © 2025 · Medical Market Report. All Rights Reserved.

Go to mobile version