gorgeous full moon
The full moon of March was 221,565 miles (356,575 kilometers) on Saturday, March 19 just 50 minutes after it hit its full phase, making it the biggest and brightest full moon since 1993. The “supermoon” phenomenon occurred because the moon was in its full phase and just 50 minutes past perigee – the point of its orbit that brings it closer to Earth
“The full Moon of March 19th occurs less than one hour away from perigee – a near-perfect coincidence that happens only 18 years or so,” Geoff Chester of the US Naval Observatory said in a NASA report. From one orbit to the next, perigees and apogees vary. Tonight’s perigee will bring the moon about as close as it ever gets.
According to NASA, perigee moons are about 14 percent larger, and 30 percent brighter than apogee moons, though it’s hard to tell the difference with the naked eye. For the best view of the supermoon, NASA has suggested viewing it when it’s lower in the sky.
According to Dr. James Garvin, chief scientist at NASA’s Goddard Space Flight Center, a ‘Supermoon’ is a situation when the moon is slightly closer to Earth in its orbit than on average, and this effect is most noticeable when it occurs at the same time as a full moon. So, the moon may seem bigger although the difference in its distance from Earth is only a few percent at such times.
It is called a supermoon because this is a very noticeable alignment that at first glance would seem to have an effect. The ‘super’ in supermoon is really just the appearance of being closer, but unless we were measuring the Earth-Moon distance by laser rangefinders (as we do to track the LRO [Lunar Reconnaissance Orbiter] spacecraft in low lunar orbit and to watch the Earth-Moon distance over years), there is really no difference. The supermoon really attests to the wonderful new wealth of data NASA’s LRO mission has returned for the Moon, making several key science questions about our nearest neighbor all the more important.