(The Washington Times)-WASHINGTON, June 21, 2013- Stargazers and amateur astronomers get a rare chance to view a special supermoon this weekend. The full moon on June 23 will be the largest full moon of the year, as well as the closest the moon will come to our planet in all of 2013. All you need to do to see the supermoon is to look up at a clear sky.
Known to astronomers as a perigee full moon, “perigee” refers to the point in the moon’s orbit where it is closest to the center of the Earth during a given month. Full moons do not always happen during a perigee and this is one not to be missed. At this point, the sun, Earth, and moon align, with the Earth in the middle.
Even though last month’s full moon was also a supermoon, this one will be even more super because the timing of the full moon will be closer to the time of perigee. The closer the time of the full moon is to the time of perigee, the larger and brighter the moon will appear. This month’s full moon and perigee come within one hour of each other.
At this point, the moon will be 221,824 miles away—30,000 miles closer than at its furthest point (known as apogee).
“Given the change in distance between the moon’s farthest and closest points,” says Larry Sessions of EarthSky, “the full moon can appear as much as 14% larger in the sky and 30% brighter to our eyes than at minimum size and brightness.”
The moon will be best viewed on the nights of June 22 and 23. A moon of larger size and proximity will not come again until September of 2015.
Affecting tides, a perigee full moon can cause a high tide that is a few inches higher than normal.
The word “supermoon” was first used 30 years ago by astrologer (not astronomer) Richard Nolle, but has only come into popular usage since 2011, when it was used to describe the March 19 full moon, the closest and largest of that year. Nolle defines supermoon as “a new or full moon which occurs with the moon at or near (within 90 percent of) its closest approach to Earth in a given orbit”.
According to the Old Farmer’s Almanac, the June moon is also known as the Full Strawberry Moon because it was the time when Algonquin tribes picked the ripened fruit. In Europe, where strawberries are not native, the June moon is known as the Full Rose Moon.