January 1, 2018 full supermoon over Seattle, Washington from Gary Peltz. See more photos of the January 1, 2018 supermoon.
A supermoon is a new or full moon closely coinciding with perigee – the moon’s closest point to Earth in its monthly orbit. An astrologer, Richard Nolle, coined the term supermoon over 30 years ago, but now many in astronomy use it as well. Supermoons have entered the popular culture (check out Sophie Hunger’s music video in this post, for example), and they can cause real physical effects, such as particularly high and low tides. According to the definition of supermoon coined by Nolle, the full moon of December was 2017’s only full supermoon. January, 2018 will have two full moons – on January 1 and 31 – and both are supermoons. Follow the links below to learn more about supermoons.
What did astronomers call these moons before “supermoons?”
Spring tides accompany the supermoons
Dates of closest full supermoons in past and future years
Enjoying EarthSky so far? Sign up for our free daily newsletter today!
Join the Virtual Telescope Project in Rome for an online viewing of the January 31, 2018 supermoon and total lunar eclipse. It’ll be a double event, covering both the lunar eclipse from Australia and the U.S. and the supermoon rising above the legendary skyline of Rome, Italy.
Rays of the rising supermoon on January 1, 2018. A supermoon doesn’t necessarily look bigger in the sky (although photos will show it is bigger). But it does look noticeably brighter! Eliot Herman in Tucson, Arizona said 2018’s supermoon – the closest supermoon of the year – was “almost blindingly bright! This is a 9-image HDR merged in Photoshop and processed with efex. Each image is spaced by 0,3 stops.”See more photos of the January 1, 2018 supermoon.
When is the next supermoon? By Richard Nolle’s definition, a new moon or full moon has to come within about 361,000 kilometers (224,000 miles) of our planet, as measured from the centers of the moon and Earth, in order to be considered a supermoon.
By that definition, the two full moons in January 2018 are both supermoons.
The December 2017 full moon was also a supermoon.
Of this series of three supermoons (one in December 2017, two in January 2018), the January 2 supermoon was the closest and largest. Thus it was the closest and largest full supermoon of 2018.
But the January 31, 2018 supermoon is by far the coolest! Many people will call it a Blue Moon because it’ll be the second of two full moons in one calendar month. Moreover, the January 31 supermoon will stage a total eclipse of the moon.
Read more: Super Blue Moon eclipse on January 31
We can expect each full moon supermoon in this three-part succession to recur after 14 lunar months (14 returns to full moon). By the way, 14 lunar months represents a time period of about 1 year, 1 month and 18 days. In 2019, the second of three full moon supermoons will showcase the closest and largest supermoon of the series:
Full moon supermoons in 2019
Full moon distance (2019 Jan 21): 357,715 km
Full moon distance (2019 Feb 19): 356,846 km
Full moon distance (2019 Mar 21): 360,772 km
Here’s a comparison between the December 3, 2017 full moon at perigee (closest to Earth for the month) and the year’s farthest full moon in June, 2017 at apogee (farthest from Earth for the month) by Muzamir Mazlan at Telok Kemang Observatory, Port Dickson, Malaysia. More photos of the December, 2017 supermoon.
In 2018, a series of new moon supermoons will occur when the new moon closely pair ups with perigee on June 13, July 13 and August 11, 2018. The second of these three new moon supermoons on July 13, 2018, will present the closest new moon supermoon of 2018. Of course, these new moons will be invisible to the eye, unless you’re in a position to witness the partial solar eclipse on Friday, July 13, 2018.
Once again, the following “season” of three new moon supermoons in 2019 will recur after 14 lunar months (14 returns to new moon): August 1 and 30, plus September 28, 2019. Again, the second of these three new moon supermoons on August 30, 2019, will feature the closest new moon supermoon of 2019.
What is a supermoon? We confess: before a few years ago, we in astronomy had never heard that term. The term has only recently come into popular usage. Richard Nolle defined a supermoon as:
… 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.
That’s a pretty generous definition, which is why there are so many supermoons. By this definition, according to Nolle:
There are 4-6 supermoons a year on average.
Some supermoons are full moons, and some are new moons. In the year 2018, any full moon or new moon coming closer than 361,554.9 km of Earth counts as a supermoon. In 2018, the closest perigee is 356,564 km and the farthest apogee lies 406,464 km distant. This is a difference of 49,899 km, so 90% of this difference is 44,909.1 km (0.9 x 49,899 = 44,909.1). So any full moon or new moon less than 361,554.9 km (406,464 – 44,909.1 = 361,554.9) from Earth enjoys supermoon status.
Some astronomers have complained about the name … but we like it! And it’s entered the popular culture. for example, Supermoon is the title track of Sophie Hunger’s 2015 album. It’s a nice song! Check it out in the video below.
What did astronomers call these moons before “supermoons?” We called them a perigean full moon, or a perigean new moon. Perigee just means near Earth.
The moon is full, or opposite Earth from the sun, once each month. It’s new, or more or less between the Earth and sun, once each month. And, every month, as the moon orbits Earth, it comes closest to Earth. That point is called perigee. The moon always swings farthest away once each month; that point is called apogee.
No doubt about it. Supermoon is a catchier term than perigee new moon or perigee full moon.
We first became familiar with the supermoon label in the year 2011 when the media used it to describe the full moon of March 19, 2011. On that date, the full moon aligned with proxigee – the closest perigee of the year – to stage the closest, largest full moon of 2011.
About 3 or 4 times a year, the new or full moon coincides closely in time with the perigee of the moon — the point when the moon is closest to the Earth. These occurrences are often called ‘perigean spring tides.’ The difference between ‘perigean spring tide’ and normal tidal ranges for all areas of the coast is small. In most cases, the difference is only a couple of inches above normal spring tides. Image and caption via NOAA.
Around each new moon (left) and full moon (right) – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are called spring tides. A supermoon – new or full moon at its closest to Earth – accentuates these tides. Image via physicalgeography.net
Spring tides will accompany the supermoons. Will the tides be larger than usual at the next supermoon? Yes, all full moons (and new moons) combine with the sun to create larger-than-usual tides, but closer-than-average full moons (or closer-than-average new moons) elevate the tides even more.
Each month, on the day of the new moon, the Earth, moon and sun are aligned, with the moon in between. This line-up creates wide-ranging tides, known as spring tides. High spring tides climb up especially high, and on the same day low tides plunge especially low, giving rise to what’s called a perigean spring tide. If you live along an ocean coastline, watch for them! They typically follow the supermoon by a day or two.
Will these high tides cause flooding? Maybe yes, and maybe no. Flooding typically occurs when a strong weather system accompanies the spring tide.
Dates of closest full supermoons in past and future years. More often than not, the one day of the year that the full moon and perigee align also brings about the year’s closest perigee (also called proxigee). Because the moon has recurring cycles, we can count on the full moon and perigee to come in concert in periods of about one year, one month and 18 days.
A lunar month refers to the time period between successive full moons, a mean period of 29.53059 days. An anomalistic month refers to successive returns to perigee, a period of 27.55455 days. Hence:
14 lunar months x 29.53059 days = 413.428 days
15 anomalistic months x 27.55455 days = 413.318 days
Therefore, the full moon and perigee realign in periods of about 413 days (one year and 48 days). So we can figure the dates of the closest full moons (<357,000 km) in past and future years:
Extra-close perigee full moons from 2010 to 2020
2010 Jan 30 (356,593 km)
2011 Mar 19 (356,575 km)
2012 May 06 (356,955 km)
2013 Jun 23 (356,991 km)
2014 Aug 10 (356,896 km)
2015 Sep 28 (356,877 km)
2016 Nov 14 (356,509 km)
2018 Jan 02 (356,565 km)
2019 Feb 19 (356,761 km)
2020 Apr 08 (356,907 km)
There wasn’t an extra-close perigee full moon in 2017 (<357,000 km). The extra-close coincidence of full moon and perigee didn't happen again (after November 14, 2016) until January 1-2, 2018. Looking further into the future, the perigee full moon will come closer than 356,500 kilometers for the first time in the 21st century (2001-2100) on November 25, 2034 (356,446 km). The closest full moon of the 21st century will fall on December 6, 2052 (356,425 km). By the way, some astronomers will call all the full moons listed above proxigee full moons.
But, like many of you, we’ll have fun just calling ’em supermoons.
What does a full supermoon look like? Most astronomers say you can’t really detect any difference with your eye between a supermoon and any ordinary full moon, although some careful observers say you can. This great moon photo is from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.
Bottom line: The January 31, 2018 full supermoon is also a Blue Moon, and it will undergo an eclipse.
Read more: Super Blue Moon eclipse on January 31
Read more: When is the next Blue Moon?
Read more: Tides and the pull of the moon and sun
from EarthSky http://ift.tt/12MniMw
January 1, 2018 full supermoon over Seattle, Washington from Gary Peltz. See more photos of the January 1, 2018 supermoon.
A supermoon is a new or full moon closely coinciding with perigee – the moon’s closest point to Earth in its monthly orbit. An astrologer, Richard Nolle, coined the term supermoon over 30 years ago, but now many in astronomy use it as well. Supermoons have entered the popular culture (check out Sophie Hunger’s music video in this post, for example), and they can cause real physical effects, such as particularly high and low tides. According to the definition of supermoon coined by Nolle, the full moon of December was 2017’s only full supermoon. January, 2018 will have two full moons – on January 1 and 31 – and both are supermoons. Follow the links below to learn more about supermoons.
What did astronomers call these moons before “supermoons?”
Spring tides accompany the supermoons
Dates of closest full supermoons in past and future years
Enjoying EarthSky so far? Sign up for our free daily newsletter today!
Join the Virtual Telescope Project in Rome for an online viewing of the January 31, 2018 supermoon and total lunar eclipse. It’ll be a double event, covering both the lunar eclipse from Australia and the U.S. and the supermoon rising above the legendary skyline of Rome, Italy.
Rays of the rising supermoon on January 1, 2018. A supermoon doesn’t necessarily look bigger in the sky (although photos will show it is bigger). But it does look noticeably brighter! Eliot Herman in Tucson, Arizona said 2018’s supermoon – the closest supermoon of the year – was “almost blindingly bright! This is a 9-image HDR merged in Photoshop and processed with efex. Each image is spaced by 0,3 stops.”See more photos of the January 1, 2018 supermoon.
When is the next supermoon? By Richard Nolle’s definition, a new moon or full moon has to come within about 361,000 kilometers (224,000 miles) of our planet, as measured from the centers of the moon and Earth, in order to be considered a supermoon.
By that definition, the two full moons in January 2018 are both supermoons.
The December 2017 full moon was also a supermoon.
Of this series of three supermoons (one in December 2017, two in January 2018), the January 2 supermoon was the closest and largest. Thus it was the closest and largest full supermoon of 2018.
But the January 31, 2018 supermoon is by far the coolest! Many people will call it a Blue Moon because it’ll be the second of two full moons in one calendar month. Moreover, the January 31 supermoon will stage a total eclipse of the moon.
Read more: Super Blue Moon eclipse on January 31
We can expect each full moon supermoon in this three-part succession to recur after 14 lunar months (14 returns to full moon). By the way, 14 lunar months represents a time period of about 1 year, 1 month and 18 days. In 2019, the second of three full moon supermoons will showcase the closest and largest supermoon of the series:
Full moon supermoons in 2019
Full moon distance (2019 Jan 21): 357,715 km
Full moon distance (2019 Feb 19): 356,846 km
Full moon distance (2019 Mar 21): 360,772 km
Here’s a comparison between the December 3, 2017 full moon at perigee (closest to Earth for the month) and the year’s farthest full moon in June, 2017 at apogee (farthest from Earth for the month) by Muzamir Mazlan at Telok Kemang Observatory, Port Dickson, Malaysia. More photos of the December, 2017 supermoon.
In 2018, a series of new moon supermoons will occur when the new moon closely pair ups with perigee on June 13, July 13 and August 11, 2018. The second of these three new moon supermoons on July 13, 2018, will present the closest new moon supermoon of 2018. Of course, these new moons will be invisible to the eye, unless you’re in a position to witness the partial solar eclipse on Friday, July 13, 2018.
Once again, the following “season” of three new moon supermoons in 2019 will recur after 14 lunar months (14 returns to new moon): August 1 and 30, plus September 28, 2019. Again, the second of these three new moon supermoons on August 30, 2019, will feature the closest new moon supermoon of 2019.
What is a supermoon? We confess: before a few years ago, we in astronomy had never heard that term. The term has only recently come into popular usage. Richard Nolle defined a supermoon as:
… 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.
That’s a pretty generous definition, which is why there are so many supermoons. By this definition, according to Nolle:
There are 4-6 supermoons a year on average.
Some supermoons are full moons, and some are new moons. In the year 2018, any full moon or new moon coming closer than 361,554.9 km of Earth counts as a supermoon. In 2018, the closest perigee is 356,564 km and the farthest apogee lies 406,464 km distant. This is a difference of 49,899 km, so 90% of this difference is 44,909.1 km (0.9 x 49,899 = 44,909.1). So any full moon or new moon less than 361,554.9 km (406,464 – 44,909.1 = 361,554.9) from Earth enjoys supermoon status.
Some astronomers have complained about the name … but we like it! And it’s entered the popular culture. for example, Supermoon is the title track of Sophie Hunger’s 2015 album. It’s a nice song! Check it out in the video below.
What did astronomers call these moons before “supermoons?” We called them a perigean full moon, or a perigean new moon. Perigee just means near Earth.
The moon is full, or opposite Earth from the sun, once each month. It’s new, or more or less between the Earth and sun, once each month. And, every month, as the moon orbits Earth, it comes closest to Earth. That point is called perigee. The moon always swings farthest away once each month; that point is called apogee.
No doubt about it. Supermoon is a catchier term than perigee new moon or perigee full moon.
We first became familiar with the supermoon label in the year 2011 when the media used it to describe the full moon of March 19, 2011. On that date, the full moon aligned with proxigee – the closest perigee of the year – to stage the closest, largest full moon of 2011.
About 3 or 4 times a year, the new or full moon coincides closely in time with the perigee of the moon — the point when the moon is closest to the Earth. These occurrences are often called ‘perigean spring tides.’ The difference between ‘perigean spring tide’ and normal tidal ranges for all areas of the coast is small. In most cases, the difference is only a couple of inches above normal spring tides. Image and caption via NOAA.
Around each new moon (left) and full moon (right) – when the sun, Earth, and moon are located more or less on a line in space – the range between high and low tides is greatest. These are called spring tides. A supermoon – new or full moon at its closest to Earth – accentuates these tides. Image via physicalgeography.net
Spring tides will accompany the supermoons. Will the tides be larger than usual at the next supermoon? Yes, all full moons (and new moons) combine with the sun to create larger-than-usual tides, but closer-than-average full moons (or closer-than-average new moons) elevate the tides even more.
Each month, on the day of the new moon, the Earth, moon and sun are aligned, with the moon in between. This line-up creates wide-ranging tides, known as spring tides. High spring tides climb up especially high, and on the same day low tides plunge especially low, giving rise to what’s called a perigean spring tide. If you live along an ocean coastline, watch for them! They typically follow the supermoon by a day or two.
Will these high tides cause flooding? Maybe yes, and maybe no. Flooding typically occurs when a strong weather system accompanies the spring tide.
Dates of closest full supermoons in past and future years. More often than not, the one day of the year that the full moon and perigee align also brings about the year’s closest perigee (also called proxigee). Because the moon has recurring cycles, we can count on the full moon and perigee to come in concert in periods of about one year, one month and 18 days.
A lunar month refers to the time period between successive full moons, a mean period of 29.53059 days. An anomalistic month refers to successive returns to perigee, a period of 27.55455 days. Hence:
14 lunar months x 29.53059 days = 413.428 days
15 anomalistic months x 27.55455 days = 413.318 days
Therefore, the full moon and perigee realign in periods of about 413 days (one year and 48 days). So we can figure the dates of the closest full moons (<357,000 km) in past and future years:
Extra-close perigee full moons from 2010 to 2020
2010 Jan 30 (356,593 km)
2011 Mar 19 (356,575 km)
2012 May 06 (356,955 km)
2013 Jun 23 (356,991 km)
2014 Aug 10 (356,896 km)
2015 Sep 28 (356,877 km)
2016 Nov 14 (356,509 km)
2018 Jan 02 (356,565 km)
2019 Feb 19 (356,761 km)
2020 Apr 08 (356,907 km)
There wasn’t an extra-close perigee full moon in 2017 (<357,000 km). The extra-close coincidence of full moon and perigee didn't happen again (after November 14, 2016) until January 1-2, 2018. Looking further into the future, the perigee full moon will come closer than 356,500 kilometers for the first time in the 21st century (2001-2100) on November 25, 2034 (356,446 km). The closest full moon of the 21st century will fall on December 6, 2052 (356,425 km). By the way, some astronomers will call all the full moons listed above proxigee full moons.
But, like many of you, we’ll have fun just calling ’em supermoons.
What does a full supermoon look like? Most astronomers say you can’t really detect any difference with your eye between a supermoon and any ordinary full moon, although some careful observers say you can. This great moon photo is from EarthSky Facebook friend Rebecca Lacey in Cambridge, Idaho.
Bottom line: The January 31, 2018 full supermoon is also a Blue Moon, and it will undergo an eclipse.
Read more: Super Blue Moon eclipse on January 31
Read more: When is the next Blue Moon?
Read more: Tides and the pull of the moon and sun
from EarthSky http://ift.tt/12MniMw
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