NASA News: Is The Moon Lopsided?

It is interesting to notice that the moon's gravitational pull seems higher on one side than the other. NASA explains this mysterious phenomenon through its Gravity Recovery and Interior Laboratory (GRAIL).

According to NASA, the Earth's Moon is the fifth largest moon in the Solar System, with a distance of 238,855 miles from our planet.

Looking at what appears to be a lopsided celestial body composed of iron core, mantle of rocks and approximately a 21 to 27-mile crust, people are hypothesizing that the rocks are denser on the nearer side than the other, according to Forbes.

In 2012, NASA conducted a gravitational field mapping using two satellites named Ebb and Flow to measure the lunar gravity with high spatial resolution and supreme accuracy. In NASA's published image, the red area shows mass excesses, while the blue area displays mass deficiencies. According to the map, the near side has a more detailed scale than the far side due to the far side's higher number of small craters.

"We used gradients of the gravity field in order to highlight smaller and narrower structures than could be seen in previous datasets," said GRAIL guest scientist Jeff Andrews-Hanna from Colorado School of Mines in Golden.

"This data revealed a population of long, linear gravity anomalies, with lengths of hundreds of kilometers, crisscrossing the surface. These linear gravity anomalies indicate the presence of dikes, or long, thin, vertical bodies of solidified magma in the subsurface. The dikes are among the oldest features on the moon, and understanding them will tell us about its early history."

Meanwhile, NASA concludes that it is misleading when people call the far side of the Moon as the "dark side" just because we could only see one side of it as it orbits the Earth. The Sun's changing illumination explains why the moon go through its phases and then it is completely illuminated during "full moon."