News / Science & Technology

    NASA Observes Moon's Tidal Bulge from Lunar Orbit

    Illustration of Earth as seen from the moon. The gravitational tug-of-war between Earth and the moon raises a small bulge on the moon. The position of this bulge shifts slightly over time.
    Illustration of Earth as seen from the moon. The gravitational tug-of-war between Earth and the moon raises a small bulge on the moon. The position of this bulge shifts slightly over time.

    Related Articles

    Video Private Space Race Heats Up

    Both SpaceX and rival Virgin Galactic make progress toward manned space operations

    Massive Martian Volcano Could Have Hosted Life

    The volcano Arsia Mons, while still active, was covered by an enormous glacier around 210 million years ago

    New ISS Crew Arrives Safely to Begin Six-Month Mission

    The Russian and US space agencies have continued to cooperate despite friction between Moscow and Washington
    VOA News
    The moon’s gravity is responsible for the rise and fall of the ocean’s tides, but the Earth has a similar effect on the moon.
     
    Scientists at the U.S. space agency, NASA, say they’ve been able to observe, for the first time from lunar orbit, a “bulge” in the moon caused by the “gravitational tug-of-war with Earth.”

    “The deformation of the moon due to Earth’s pull is very challenging to measure, but learning more about it gives us clues about the interior of the moon,” said Erwan Mazarico, a scientist with the Massachusetts Institute of Technology in Cambridge, Mass., who works at NASA’s Goddard Space Flight Center in a statement.

    NASA scientists said the gravitational effects on both the Earth and moon are powerful enough to stretch them enough “so they wind up shaped a little like two eggs with their ends pointing toward one another.”

    While we can observe the moon’s effect on Earth by watching the ocean’s tides, the effect on the moon is harder to observe because the moon is basically solid except for a small core. Also, only one side of the moon faces the Earth.

    Still, scientists said the Earth’s gravity is strong enough to create a 51 centimeter high bulge on both the near and far sides of the moon.

    NASA said the lunar bulge “shifts a few inches over time,” responding “to Earth’s movements like a dance partner, following wherever the lead goes.”

    The NASA scientists used data from the Lunar Reconnaissance Orbiter, which has been investigating the moon since 2009, and from the Gravity Recovery and Interior Laboratory, or GRAIL, mission. This allowed them to observe the entire moon rather than the one side that constantly faces Earth.

    Using the altimeter aboard the LRO, to measure 350,000 locations on the lunar surface. They then compared changes in altitude to see how the bulge had moved.

    The study was published online in Geophysical Research Letters.

    You May Like

    Syrian Torture Victim Recounts Horrors

    'You make them think you have surrendered' says Jalal Nofal, a doctor who was jailed and survived repeated interrogations in Syria

    Mandela’s Millions Paid to Heirs, But Who Gets His Country Home?

    Saga around $3 million estate of country's first democratic president is far from over as Winnie Mandela’s fight for home overshadows payouts

    Guess Which Beach is 'Best in the US'?

    Hawaii’s Hanauma Bay tops an annual "top 10" list compiled by a coastal scientist, also known as Doctor Beach

    This forum has been closed.
    Comment Sorting
    Comments
         
    by: Mark from: Virginia
    June 03, 2014 7:05 AM
    Sagan (from EarthIThink), you are SO right...we are, in fact just as they movie The Matrix suggests we are, under the control of a computer program that is feeding us its definition of 'existence' while we are connected with wires and tubes to power the machines that hold us as slaves. This is all a big fake and a lie, this life we lead. We all live in a postage stamp sized creation in our minds, with thoughts put there by artificial intelligence.

    End Sarcasm.

    by: Censorship from: Inside Earth
    May 31, 2014 7:50 PM
    Periods of history with censorship are referred to as DARK AGES.

    by: Sagan from: earthIthink
    May 31, 2014 7:49 PM
    The stars truly are amazing once you get out of the atmosphere that diffuses all that light....
    No wonder they put telescopes on mountains.
    Not that NASA would ever show us a photo of stars from the moon at night.
    No, then it would be too easy to see that this is all FAKE.
    The earth does not rotate. Nor is it a globe (well a concave one maybe but not a billiard ball)
    Easy to prove.
    So this photo cannot be real.
    If the Earth were a globe shooting through space at 17.6 miles per second IN A CIRCLE. AND spinning at 1000MPH at its equator (dizzy there in equador?) then I couldn't type this sentence because I wouldn't be able to BREATHE since the atmosphere would have whooshed away about a million years ago. Try to get air to stick to a ball. And then spin with it at 1000MPH. LOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOLOL
    :)
    Oh what fools we all are.

    by: Cranksy from: USA
    May 31, 2014 2:12 PM
    “[So] they wind up...with their ends pointing toward one another.” It is as if the Earth and moon are trying to "moon" one another.

    Featured Videos

    Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
    Chinese-Americans Heart Trump, Bucking National Trendi
    X
    May 27, 2016 5:57 AM
    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Chinese-Americans Heart Trump, Bucking National Trend

    A new study conducted by three Asian-American organizations shows there are three times as many Democrats as there are Republicans among Asian-American voters, and they favor Hillary Clinton over Donald Trump. But one group, called Chinese-Americans For Trump, is going against the tide and strongly supports the business tycoon. VOA’s Elizabeth Lee caught up with them at a Trump rally and reports from Anaheim, California.
    Video

    Video Reactions to Trump's Success Polarized Abroad

    What seemed impossible less than a year ago is now almost a certainty. New York real estate mogul Donald Trump has won the number of delegates needed to secure the Republican presidential nomination. The prospect has sparked as much controversy abroad as it has in the United States. Zlatica Hoke has more.
    Video

    Video Drawings by Children in Hiroshima Show Hope and Peace

    On Friday, President Barack Obama will visit Hiroshima, Japan, the first American president to do so while in office. In August 1945, the United States dropped an atomic bomb on the city to force Japan's surrender in World War II. Although their city lay in ruins, some Hiroshima schoolchildren drew pictures of hope and peace. The former students and their drawings are now part of a documentary called “Pictures from a Hiroshima Schoolyard.” VOA's Deborah Block has the story.
    Video

    Video Vietnamese Rapper Performs for Obama

    A prominent young Vietnamese artist told President Obama said she faced roadblocks as a woman rapper, and asked the president about government support for the arts. He asked her to rap, and he even offered to provide a base beat for her. Watch what happened.
    Video

    Video Roots Run Deep for Tunisia's Dwindling Jewish Community

    This week, hundreds of Jewish pilgrims are defying terrorist threats to celebrate an ancient religious festival on the Tunisian island of Djerba. The festivities cast a spotlight on North Africa's once-vibrant Jewish population that has all but died out in recent decades. Despite rising threats of militant Islam and the country's battered economy, one of the Arab world's last Jewish communities is staying put and nurturing a new generation. VOA’s Lisa Bryant reports.
    Video

    Video Meet Your New Co-Worker: The Robot

    Increasing numbers of robots are joining the workforce, as companies scale back and more processes become automated. The latest robots are flexible and collaborative, built to work alongside humans as opposed to replacing them. VOA’s Tina Trinh looks at the next generation of automated employees helping out their human colleagues.
    Video

    Video Wheelchair Technology in Tune With Times

    Technologies for the disabled, including wheelchair technology, are advancing just as quickly as everything else in the digital age. Two new advances in wheelchairs offer improved control and a more comfortable fit. VOA's George Putic reports.
    Video

    Video Baby Boxes Offer Safe Haven for Unwanted Children

    No one knows exactly how many babies are abandoned worldwide each year. The statistic is a difficult one to determine because it is illegal in most places. Therefore unwanted babies are often hidden and left to die. But as Erika Celeste reports from Woodburn, Indiana, a new program hopes to make surrendering infants safer for everyone.
    Video

    Video California Celebration Showcases Local Wines, Balloons

    Communities in the U.S. often hold festivals to show what makes them special. In California, for example, farmers near Fresno celebrate their figs and those around Gilmore showcase their garlic. Mike O'Sullivan reports that the wine-producing region of Temecula offers local vintages in an annual festival where rides on hot-air balloons add to the excitement.
    Video

    Video US Elementary School Offers Living Science Lessons

    Zero is not a good score on a test at school. But Discovery Elementary is proud of its “net zero” rating. Net zero describes a building in which the amount of energy provided by on-site renewable sources equals the amount of energy the building uses. As Faiza Elmasry tells us, the innovative features in the building turn the school into a teaching tool, where kids can't help but learn about science and sustainability. Faith Lapidus narrates.

    Special Report

    Adrift The Invisible African Diaspora