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

Phases of the Moon

Moon phases depend on the position of both the Sun and Moon with respect to the Earth. The 4 primary phases of the Moon are: new, first quarter, full and third quarter.

Time lapse picture of Moon phases
The phases of the Moon.
©bigtockphoto.com/Petr Jilek

The intermediate phases between the primary phases are, waxing crescent, waxing gibbous, waning gibbous, and waning crescent.

New Moon

A new moon is the moment when the Sun and Moon are in conjunction, meaning that the Sun and Earth are on the opposite sides of the Moon.

A New Moon cannot normally be seen from the Earth since only the dark side of the Moon faces the Earth at New Moon. Sometimes, if the New Moon is close to the Lunar nodes of its path, it causes a Solar Eclipse.

New Moon Phase
New Moon: The darkest Moon Phase.

Waxing Crescent Moon

A few days after the new moon phase, the Moon will be visible again in a phase that lasts until the first quarter, called waxing crescent moon. The initial period, just after the Moon becomes visible, is sometimes called new moon, although it has another definition. Although only a small part of the Moon may be illuminated by the Sun, the rest of the Moon may also be faintly visible, due to a reflection from the Earth to the Moon, called earthshine. The waxing crescent moon is most visible after sunset. The first visual sight of the waxing crescent moon determines the beginnings of months in the Muslim calendar.

First Quarter Moon

First Quarter Moon Phase
First Quarter Moon is the second Phase.

During the first quarter, half of the Moon is illuminated, as seen from the Earth. The Moon rises near the middle of the day and sets near the middle of the night. In northern regions of the world, the right part will be visible, while the left part will be visible in the southern regions. Near the equator, the upper part is bright after moonrise, and the lower part is bright before moonset (the bright part appears and disappears first).

Waxing Gibbous Moon

The waxing gibbous moon occurs between the first quarter and the full moon. The sun illuminates more than half of the Moon’s surface during this period.

Full Moon

Full Moon Phase
Full Moon is the brightest phase.

Each Full Moon has a name
…unless it’s a Blue Moon

Full moon appears when the Sun and the Moon are on opposite sides of the Earth. As seen from Earth, all of the Moon’s surface will be visible.

The full moon is visible approximately from sunset to sunrise. When observed from Earth, the Moon can appear to be full for a couple of days, since more than 98 percent of the Moon’s disc is illuminated a day before or after the full moon. During full moon, the Moon may pass through Earth’s shadow causing a lunar eclipse. If the whole moon is in the Earth’s shadow, or umbra, a total lunar eclipse occurs. If only a part of the Moon enters the umbra, we see a partial lunar eclipse.

Waning Gibbous Moon

The period between full moon and third quarter is called waning gibbous moon. The portion of the visible half of the Moon illuminated goes down from 100 percent to 50 percent during this period.

Third Quarter Moon

Illustration image
Third Quarter Moon is the last phase.

The third quarter moon occurs when the other half of the Moon is illuminated compared to the first quarter. On the day of third quarter, the Moon rises approximately in the middle of the night and sets in the middle of the day.

Waning Crescent Moon

The waning crescent moon is the period between the third quarter moon and the next new moon. It is most visible before sunrise. The Sun illuminates less than half the Moon during this period. When only a small part of the Moon is visible, it may be possible to see earthshine on the dark side of the Moon.

Lunation

A lunation is a cycle of the Moon. It starts at new moon and lasts until the next new moon.

Lunations & Moon Phases worldwide

On average, it takes the Moon 29 days 12 hours 44 minutes to go from one new Moon to the next. This time frame is called a synodic month. The duration of a synodic month varies from one lunation to another, most importantly because the orbit of the Earth and Moon are ellipses rather than circles, where the orbit speed depends on how close the orbiting object is to the mass center. For example, the Moon moves faster when it is closest to the Earth. Some years, such as 2004, have relatively small duration differences throughout the year (five hours difference between minimum and maximum duration), while the year 2008 will have larger differences (more than twelve hours).

Topics: Astronomy, Moon, Sun, Earth

From: http://www.timeanddate.com/calendar/aboutmoonphases.html

What is a Black Moon?

There are several definitions of Black Moon. It can be the third New Moon in an astronomical season with four New Moons or the second New Moon in the same calendar month.

Illustration image
A Black Moon can be a New Moon.
©bigstockphoto.com/mr. Smith

Black Moon is not a well known term in the astronomy world. In recent years, the term has been made popular by astrologers and followers of the Wiccan religion.

No Single Definition

There is no single accepted definition of a Black Moon. The term has been commonly used to refer to any of the following phenomena associated with the New Moon:

  • Second New Moon in a calendar month: These Black Moons occur relatively often – once every 2.5 years.
  • Third new moon in a season of four New Moons: Astronomers divide a year into fourseasons – spring, summer, fall (autumn), and winter. Usually, each season has 3 months and 3 New Moons. When a season has 4 New Moons, the 3rd New Moon is called a Black Moon.
  • A calendar month without a New Moon: This can only happen in the month of February. When this occurs, January and March will have two New Moons, instead of the usual one New Moon.
  • A calendar month without a Full Moon: About once every 19 years, the month of February does not have a Full Moon. Instead, January and March have two Full Moons each. The next Black Moon by this definition will occur in February 2018.

Upcoming Black Moon

October 2016 will have two New Moons – on October 1, 2016 and on October 30, 2016. The second New Moon on October 30, 2016 will be a Black Moon.

Year Date/Month Type
2016 Sep 30 Second New Moon in a single calendar month
2017 Aug 21 Third New Moon in a season with four New Moons
2018 Feb Calendar month without a Full Moon

Ritual Significance

Black Moons hold special significance to people who practise certain forms of Pagan religions and who believe certain actions become more potent when performed on the night of a Black Moon.

Blue Moon

Blue Moon is a term used to descibe various combinations of Full Moons. It can either be the second Full Moon in the same calendar month or the third Full Moon in an astronomical season of four Full Moons.

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

What & When is a Blue Moon?

There are two astronomical definitions of a Blue Moon; both are a type of Full Moon. When the Moon very rarely actually looks blue, it’s because of a certain size dust particles in the atmosphere.

Illustration image
Blue moons are rarely blue
©bigstockphoto.com/Kamira

The next Blue Moons

Year Date
2015 Friday, July 31
2016 Saturday, May 21

Once in a blue moon means very rarely. But just how rare depends on your definition.

In astronomy, Blue Moon is defined as either the third full moon of an astronomical season with four full moons or the second full moon in a calendar month.

Such a blue Moon (second full Moon in single calendar month) will next occur on Friday, July 31, 2015 at 10:43 am UTC.

Contrary to popular belief, a blue moon is not actually blue in color. Blue moon is a term that is used to describe the third full moon of a season that has four full moons.

A year has four seasons – Spring, Summer, Fall (Autumn), and Winter – with three months and three full moons each. When one of the seasons in a year has four full moons, instead of the usual three, the third full moon is called a blue moon.

These days, the second full moon in a calendar month is also often referred to as a blue moon. This particular use was popularized due to a misinterpretation in a 1946 article in Sky and Telescope magazine. Such blue moons occur rather frequently – at least once every two or three years. The next such blue moon will occur on July 31, 2015.

Are blue Moons rare?

Blue colored moons do rarely occur when dust or smoke particles in the air are of a specific size. Such particles help create a blue colored moon by scattering blue light.

Red moons, which can be caused by other sizes of dust particles or lunar eclipses, are much more common than blue moons.

The phrase, once in a blue moon, is colloquially used to suggest that something is very rare.

Why the third Moon?

There are different accounts of why the third full moon of a season of four full moons is called a blue moon.

For instance, the Ecclestical calendar, which indicates the dates of the Christian fasts and festivals, uses the phases of the moon to determine the exact dates for holidays like Lent and Easter. The month of Lent contains the Lenten Moon. The first full moon of Spring – also known as Easter Moon or Paschal Moon – falls a week before Easter. In order to ensure that Lent and Easter coincides with the phases of the moon, the calendar has termed the third moon of the season as the blue moon.

Another version of this is that since each full moon of a normal year already has a given name, for instance Harvest Moon, the 13th nameless full moon in a year was named a blue moon. This way the lunations and calendars werw aligned to make sure celebrations and customs would still fall during their “proper” times.

Did you know?

About once every 19 years, the month of February does not have a full moon. The years when this happens, also have two full moons in two different months. This phenomenon will occur next in 2018.

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