The first supermoon in almost six months will take place Friday.
A supermoon is scheduled to take place on July 12, the first one since January 30.
Supermoons refer to when the moon is slightly closer to Earth in its orbit than usual.
The effect of the closer orbit is most noticeable when there is 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,” said Dr. James Garvin, chief scientist at NASA’s Goddard Space Flight Center on the space agency’s website. “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.”
“The scientific term for the phenomenon is ‘perigee moon.’ Full Moons vary in size because of the oval shape of the Moon’s orbit. The Moon follows an elliptical path around Earth with one side (‘perigee’) about 50,000 km closer than the other (‘apogee’),” added NASA.
“Full Moons that occur on the perigee side of the Moon’s orbit seem extra big and bright.”
Because of how close the supermoon is, it can appear as much as 14 percent larger in the sky and 30 percent brighter to our eyes than normal moons, according to NASA.
Supermoons are typically visible once it becomes dark out.
The two other ones forecasted for this year are August 10 and September 9. The one is August is supposed to be the closet to Earth.
The term supermoon came from astrologer Richard Nolle over 30 years ago, and is only now coming into popular usage, according to EarthSky. Nolle said a supermoon is “a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit.”
Before supermoons were called supermoons, they were referred to perigee full moon, or perigee new moon. Perigee means “the point in the orbit of the moon or a satellite at which it is nearest to the earth,” being derived from the Greek word perigeion, which meant “close around the Earth.”