NASA’s Lunar Reconnaissance Orbiter (LRO) has taken pictures of the moon’s crust that reveal that recent geological activity may have occurred, according to a NASA press release. The images from the Lunar Reconnaissance Orbiter Camera (LROC) demonstrate that the moon’s crust is being pulled apart, which in turn is creating small valleys on the lunar surface. Scientists believe that any geological activity on the moon may have occurred less than 50 million years ago. Although 50 million years is a lot of time by human standards, the moon is approximately 4.4 billion years old.
“We think they’re less than 50 million years old, but they could be 10 million years old, could be 1 million years old, could have happened 40 years ago,” Thomas Watters of the Center for Earth and Planetary Studies at the Smithsonian’s National Air and Space Museum in Washington told SPACE.com. “The intriguing picture that’s emerging of the moon is that there is recent geological activity going on,” Mr. Watters added.
A team of scientists examining the LROC’s pictures found small, skinny trenches that are much longer than they are wide. The trenches reveal that the moon’s crust is being stretched apart at these locations. Also known as graben, these linear valleys are created when the moon’s crust is pulled, breaks and drops down along two bounding faults. The graben found in the LROC’s pictures have also been found in other locations along the moon’s surface.
“We think the moon is in a general state of global contraction because of cooling of a still hot interior,” Mr. Watters professed. “The graben tell us forces acting to shrink the moon were overcome in places by forces acting to pull it apart. This means the contractional forces shrinking the moon cannot be large, or the small graben might never form,” he added.
The study’s findings reveal that the moon did not completely melt during the early stages of its formations. The existence of graben suggest that while the moon’s exterior melted, the rest of the moon did not.
Starting in August 2010, the team of researchers studied pictures from the LROC to find signs of contraction on the moon’s surface. The researchers were looking for lobate scarps. According to Science 2.0, lobate scarps are thrust faults that indicate that the moon shrank in the past and that it may still be shrinking. Lobate scarps were first seen in photographs taken by the Apollo 15, 16 and 17 missions.
The existence of graben on the moon’s surface suggests that there are also forces on the moon’s crust acting to pull it apart.
“This pulling apart tells us the moon is still active,” said Richard Vondrak, LRO Project Scientist at NASA’s Goddard Space Flight Center. “LRO gives us a detailed look at that process,” Mr. Vondrak added.
The LRO will continue to give scientists an idea of how many graben exist on the lunar surface and what forces are continually acting on the moon’s crust.
“It was a big surprise when I spotted graben in the far side highlands,” said the study’s co-author Mark Robinson of the School of Earth and Space Exploration at Arizona State University. “I immediately targeted the area for high-resolution stereo images so we could create a three-dimensional view of the graben. It’s exciting when you discover something totally unexpected and only about half the lunar surface has been imaged in high resolution. There is much more of the moon to be explored,” Mr. Robinson added.
The study’s findings may be bad news for former House Speaker Newt Gingrich if he wins the Republican presidential nomination. In fact, geological activity and a number of other hazards and challenges may doom Mr. Gingrich’s moon base idea.
“By the end of my second term, we will have the first permanent base on the moon, and it will be American,” Mr. Gingrich told a group of supporters during a campaign event in Cocoa, Florida on January 25th.
Almost immediately, Mr. Gingrich’s moon base idea was slammed by his competitors and space experts. “When we are not expecting a U.S. crewed launch [...] until 2016-2017 and are just getting started on a lunar-class launch vehicle, establishing a lunar outpost by 2020 is a fantasy,” John Logsdon, a professor emeritus at George Washington University, posited to SPACE.com in an email.
Fellow Republican presidential candidate Rick Santorum ridiculed Mr. Gingrich moon base idea prior to the Florida Republican primary. “The idea that anybody is going out and talking brand new, very expensive schemes to spend more money at a time when we do not have our fiscal house in order, in my opinion, is playing crass politics,” Mr. Santorum said at Florida State University, according to CBS News.
Universe Today highlights a large number of the roadblocks that would prevent a permanent base from being built on the moon. The blog talks about the astronomical costs, the risk of asteroid impacts and the dangers of moon dust among others.
While the Georgia Republican’s moon base idea was already likely to be too costly to ever become a reality, evidence of recent geological activity may be one more factor that doom’s Mr. Gingrich’s moon base promise.
The research for the study, “Recent extensional tectonics on the Moon revealed by the Lunar Reconnaissance Orbiter Camera,” was funded by the LRO mission, which is under NASA’s Science Mission Directorate at NASA Headquarters in Washington. The LRO is managed by NASA’s Goddard Space Flight Center.
The research appeared in the March issue of the journal Nature Geoscience.
