What Is a Supermoon ?

A supermoon happens when there’s a Full Moon or New Moon at the same time as the Moon’s closest approach to the Earth; perigee. It’s also known as Super Full Moon, Supoer New Moon and Perigee Moon.

Wat arun in night with super full moon
A Supermoon can be full or new.
©bigstockphoto.com/Prasit Rodphan

The Next Super Moons

Year Date
2015 Sunday, September 27
2016 Monday, November 14
2017 Sunday, December 3

Because the Moon’s orbit around Earth is elliptical, thedistance from moon to Earth varies throughout the month and year. On average the distance is about 238,000 miles or 382,900 kilometers.

During a month, when the moon is closest to Earth it’s called perigee and when it’s farthest away from Earth it’s called apogee.

Moon Phases worldwide

When the Full Moon or New Moon coincides with being closest to Earth, or perigee, it is called a supermoon.

When the Moon is at the opposite end, farthest from Earth, or apogee, it’s called a Micro Moon.

Defining a Supermoon

There are no universal rules as to how close the moon must be to qualify as a supermoon or a micro moon. timeanddate.com uses the following definition:

  • If a Full Moon or new moon is closer than 360,000 kilometers (ca. 223,694 miles) at perigee, it is considered a supermoon.
  • If there’s a Full Moon or New Moon when the Moon is farther than 400,000 kilometers (ca. 248,548 miles) at apogee, it’s considered a Micro Moon.

Technical Name: Syzygy

The technical term for a supermoon is “perigee-syzygy of the Earth-Moon-Sun system”. In astronomy, the term “syzygy” refers to the straight-line configuration of three celestial bodies.

Syzygy also happens during a New Moon and Full Moon, and sometimes when the Moon is close to the Lunar nodes of its path, it causes a Total Solar Eclipse or a Total Lunar Eclipse

Moon phases

Natural Disaster Trigger?

Although the sun and the moon’s alignment cause a small increase in tectonic activity, the effects of the supermoon on Earth are minor. Many scientists have conducted studies and haven’t found anything significant that can link the Super Moon to for example natural disasters.

According to NASA, the combination of the Moon being at its closest and at Full Moon, should not affect the internal energy balance of the Earth since there are lunar tides every day. There is a small difference in tidal forces exerted by the moon’s gravitational pull at lunar perigee. However, the difference is too small to overcome the larger forces within the planet.

Super Tides and Grativational Pull

Moon is Earth’s only natural satellite and the second brightest object in the sky after the sun. In synchrony with Earth, the moon spins at about the same speed and direction as it orbits around the Earth. This means that the same side always faces Earth, and the dark side of the Moon, the half of the moon’s surface which faces away, is never visible from Earth.

The tides on Earth are mostly generated by the intensity of the moon’s gravitational pull from one side of the Earth to the other. The Moon’s gravity can cause small ebbs and flows in the continents called land tides or solid Earth tides. These are greatest during the Full and New Moons because the sun and moon are aligned on the same or opposite sides of the Earth.

Topics: Astronomy, Moon

From: http://www.timeanddate.com/astronomy/moon/super-full-moon.html