This Moon Was Really Super
Saturday's full moon was the year's biggest, brightest, and closest to Earth
What’s that in the sky? It’s not a bird or a plane. It’s supermoon!
On Saturday, May 5, the world saw the biggest and brightest full moon of the year. On that night, the moon was at the closest point to Earth in its orbit. The scientific term for this is perigee, but to most people, it’s a “supermoon.”
The supermoon reached its peak at 11:34 p.m. Eastern time, when the moon aligned with the Earth and the sun. At that time, the moon was about 221,802 miles from Earth—some 15,300 miles closer than average. That made it appear about 14 percent bigger and 30 percent brighter than it does when it is farthest away from Earth. The moon’s distance from Earth varies because it follows an oval orbit rather than a circular one.
Some people worry that a supermoon could cause natural disasters. The moon’s gravitational pull on Earth causes the ebb and flow of the ocean tides. It can even cause “land tides,” which are slight movements of the continents. Full and new moons cause larger land tides, because the sun and moon are lined up on the same or opposite sides of Earth. Extreme ocean and land tides can occasionally trigger earthquakes and/or volcanic activity.
But experts say the moon’s tiny bit of extra gravitational pull during a supermoon is not enough to significantly increase the likelihood of earthquakes or volcanic eruptions. In fact, this year’s supermoon brought little more than more-detailed views of the moon’s craters and basins.
If you missed Saturday’s supermoon, you’ll have to wait a while to see another one: A supermoon happens only once a year. Last year’s supermoon, on March 19, was about 240 miles closer to Earth than this year’s. Experts say the next supermoon, on June 23, 2013, will be a bit farther away than the one in 2012.