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

Philippines, Muslim Rebels Try to Salvage Peace Pact

Peace process faces major setback after botched military operation to find terrorists results in bloody gunbattle between government forces, Moro Islamic Liberation Front fighters More

Republicans Expect Long, Expensive Presidential Battle

Political strategist says eventual winner will be one who can put together strongest coalition of various conservative groups that make up Republican Party More

Video New Wheelchair Is Easier to Use, Increases Mobility

Engineers have come up with a lever-operated design that makes use of easily accessible bicycle technology More

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.
Liberia's Almost Last Ebola Patient Grateful but Still Grievingi
X
Benno Muchler
March 26, 2015 3:41 PM
Beatrice Yardolo was to make history as Liberia’s last Ebola patient. Liberians recently started counting down 42 days, the period that has to go by without a single new infection until the World Health Organization can declare a country Ebola-free. That countdown stopped on March 20 when there was another new case of Ebola, making Yardolo’s story a reminder that Ebola is far from over. Benno Muchler reports from Monrovia.
Video

Video Liberia's Almost Last Ebola Patient Grateful but Still Grieving

Beatrice Yardolo was to make history as Liberia’s last Ebola patient. Liberians recently started counting down 42 days, the period that has to go by without a single new infection until the World Health Organization can declare a country Ebola-free. That countdown stopped on March 20 when there was another new case of Ebola, making Yardolo’s story a reminder that Ebola is far from over. Benno Muchler reports from Monrovia.
Video

Video Cambodian Land Grabs Threaten Traditional Communities

Indigenous communities in Cambodia's Ratanakiri province say the government’s economic land concession policy is taking away their land and traditional way of life, making many fear that their identity will soon be lost. Local authorities, though, have denied this is the case. VOA's Say Mony went to investigate and filed this report, narrated by Colin Lovett.
Video

Video US, South Korea Conduct Joint Military Exercises

The Eighth U.S. Army Division and the Eighth Republic of Korea Mechanized Infantry Division put on a well orchestrated show of force for the media this week during their joint military training exercises in South Korea. VOA’s Seoul correspondent Brian Padden was there and reports the soldiers were well disciplined both in conducting a complex live fire exercise and in staying on message with the press.
Video

Video Space Program Status Disappoints 'Last Man on the Moon'

One of the films that drew big crowds last week at the annual South by Southwest festival in Austin, Texas, tells the story of the last human being to stand on the moon, U.S. astronaut Eugene Cernan. It has been 42 years since Cernan returned from the moon and he laments that no one else has gone there since. VOA’s Greg Flakus reports.
Video

Video Young Filmmakers Shine Spotlight on Giving Back

A group of student filmmakers from across the United States joined President Barack Obama at the White House this month for the second annual White House Student Film Festival. Fifteen short films were officially selected from more than 1,500 entries by students aged 6 through 18. The filmmakers and their families then joined the president and a group of celebrities for a screening of their films. VOA’s Julie Taboh reports.
Video

Video VOA Exclusive: Interview with Afghan President Ashraf Ghani

Afghan President Ashraf Ghani, during his first visit as president to Washington, gave a one-on-one interview with VOA Afghan Service reporter Said Suleiman Ashna, about his request for a change in U.S. troop levels, the threat from the Islamic State, and repairing relations with the United States and Pakistan. The interview was held at Blair House, late Sunday, in Pashto.
Video

Video California Science Center Tells Story of Dead Sea Scrolls

The ancient manuscripts were uncovered in the mid-20th century, and they are still yielding clues about life and religious beliefs in ancient Israel. As VOA's Mike O'Sullivan reports, an exhibit in Los Angeles shows how modern science is bringing the history of these ancient documents to life.
Video

Video Angelina Jolie Takes Another Bold Step

Hollywood actress and filmmaker Angelina Jolie has revealed she had her ovaries and fallopian tubes removed to lower her odds of getting cancer. Doctors say the huge publicity over her decision will help raise awareness about the importance of cancer screening. VOA’s George Putic has more

All About America

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More