A supermoon will take place this weekend, delighting amateur astronomers.
As the Moon orbits around the Earth, the distance between the two bodies varies. The perigee, or nearest approach to our world by the moon, changes positions in the orbit of our planetary companion. Similar behavior affects the most distant point between the bodies in orbit, the apogee.
Supermoons occur when the perigee of the moon coincides with either a full or new moon. When this happens during a full moon, as it will this weekend, the angular size of the Moon is the largest, and brightest it will be at any point.
The closest the moon comes to the Earth is about 222,000 miles, and the satellite is roughly 252,000 miles from Earth at apogee.
Supermoons occur on an irregular schedule, although they happen at least once every 18 years.
Some people believe these events can cause disasters, including sinking ships. No such events have ever been shown to have been caused by a supermoon.
"We obviously know that there are scientific laws that say the moon affects the Earth (i.e. tides). There are also less proven theories that propose that the moon affects the Earth in other ways (i.e. abnormal behavior during a full moon)," Accuweather researchers wrote on their website.
Tidal forces on Earth are brought about by the gravitational pull of the moon and the sun. During full and new moon phases, the sun-Earth-moon trio line up in nearly a straight line, a phenomenon astronomers call syzygy. This increases tidal effects on our planet.
To view the supermoon this weekend, head out nearly anytime during the night, from Friday to Sunday. Early-evening viewers will see the moon rising in the east. Those who head out around midnight to 1 a.m. will find the moon toward the south, while viewers heading out before dawn will see out lunar companion as it sets in the west.
There is no special equipment needed to observe this phenomenon, just a horizon clear of obstructions, and skies that are not flooded with light. Some observers use a digital camera to take photographs of the moon during its close approach. The best results are obtained by mounting the camera to a tripod, and using a time delay to take the photographs. Having foreground objects, like houses and trees on the horizon in the picture helps lend a sense of scale.
This year features a total of five supermoons, two of which occurred in January. The next such event will take place on 10 August, which is also the closest approach of 2014 between the Earth and moon. Another supermoon will happen on 9 September.
Before supermoons were given their name, they were called perigee full (or new) moons. The word perigee literally translates as "near Earth."