EarthSky Science news
written by Bruce McClure and Deborah Byrd
Friday July 12, 2013
The July 2013 full moon falls on Monday, July 22, 2013 at 18:16 UTC. This month’s full moon falls one day after July’s lunar perigee, which is the moon’s closest point to Earth for this monthly orbit. Astronomers will call this full moon a perigee full moon, but everyone else will call it a supermoon, according to a definition coined in recent decades by an astrologer. Follow the links below to learn more about this supermoon.
Top of post: June 2013 supermoon over Punta Manara, Sestri Levante Italy via Maranathi.it Photography
How super is this supermoon? This July 2013 supermoon isn’t as “super” as the supermoon in June 2013. On the night of June 22-23, the moon reached the crest of its full phase within an hour of the time of perigee, or the moon’s closest point. This month, lunar perigee (closest point to Earth) and the crest of the moon’s full phase fall about a day apart.
As always, this July, although the full moon comes at the same instant for everyone worldwide, the clock reads differently according to time zone. In the United States, the July full moon will occur on July 22 at 2:16 p.m. Eastern Daylight Time, 1:16 p.m. Central Daylight Time, 12:16 p.m. Mountain Daylight Time and 11:16 a.m. Pacific Daylight Time.
For us across the United States, the moon turns astronomically full – or stands most directly opposite the sun – during the daylight hours on July 22. But for general reference, we can say the July 22 moon is full all night for us and the rest of the world.
Why so many supermoons lately? There aren’t really any more than there ever were. It’s just that people really like the term supermoon, and more and more media are using it. The July supermoon is the third full supermoon to happen in 2013. The first one was in May, and the second in June. Why so many supermoons? The reason is that the definition, as coined by astrologer Richard Nolle has 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 and allows for many supermoons. By this definition, according to Nolle:
There are 4-6 supermoons a year on average.
Tired of supermoons yet? Most people aren’t. Like many of the special full moons – such as Blue Moons – supermoons seem to have an unending allure.
The July 2013 supermoon is prelude to a Blue Moon. The July 2013 full moon presents the second full moon after the June solstice. Normally, there are only three full moons in one season – the period of time between a solstice and an equinox, or vice versa. However, in 2013, four full moons take place in between the June solstice and the September equinox.
The third of four full moons to fall in one season will occur on August 20-21, 2013, and many will call this particular full moon a Blue Moon.
In North America, we often call the July full moon the Buck Moon, Thunder Moon or Hay Moon. At this time of year, buck deer grow velvety antlers, thunderstorms rage and farmers struggle to put hay into their barns.
Will the supermoon be noticeably bigger or brighter? Unless you have super-human powers of perception and memory, you probably can’t really compare the full moon size or brightness from one month to the next. Is the July 2013 full moon actually bigger and brighter? Yes, a little bit. Can we perceive the difference? Probably not. But photographs do show the difference.
You can enjoy watching the July full moon as it beams over the eastern horizon at evening dusk on July 22. Like any full moon, the moon will look large and spectacular as it fully reflects the light of the sun.
Also, notice the path of the moon. The moon’s path across the sky tonight varies, depending on where you live worldwide, but, for all of us, the full moon’s trajectory across the sky will resemble that of the sun some six months from now, or in January. For the Northern Hemisphere, the July full moon will follow the low arc of the winter sun. As seen from the Southern Hemisphere, the path of the July full moon will mimic the high-flying summer sun.
Will the tides be higher than usual? Yes, all full moons bring higher-than-usual tides, and perigee full moons bring the highest (and lowest) tides of all. Each month, on the day of the full moon, the moon, Earth and sun are aligned, with Earth 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.
Today’s extra-close full moon accentuates these monthly (full moon) spring tides all the more.
If you live along a coastline, watch for high tides caused by the July 22 perigee full moon – or supermoon – over the next several days. Will the high tides cause flooding? Probably not, unless a strong weather system moves into the coastline where you are. Still, keep an eye on the weather, because storms do have a large potential to accentuate high spring tides.
Bottom line: The next supermoon will happen on July 22. A supermoon is a new or full moon that occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit. That’s a generous definition, which is why there are so many supermoons! The July 22, 2013 moon is the third full supermoon this year.
Will the supermoon be noticeably bigger or brighter? Unless you have super-human powers of perception and memory, you probably can’t really compare the full moon size or brightness from one month to the next. Is the July 2013 full moon actually bigger and brighter? Yes, a little bit. Can we perceive the difference? Probably not. But photographs do show the difference.
You can enjoy watching the July full moon as it beams over the eastern horizon at evening dusk on July 22. Like any full moon, the moon will look large and spectacular as it fully reflects the light of the sun.
Also, notice the path of the moon. The moon’s path across the sky tonight varies, depending on where you live worldwide, but, for all of us, the full moon’s trajectory across the sky will resemble that of the sun some six months from now, or in January. For the Northern Hemisphere, the July full moon will follow the low arc of the winter sun. As seen from the Southern Hemisphere, the path of the July full moon will mimic the high-flying summer sun.
Will the tides be higher than usual? Yes, all full moons bring higher-than-usual tides, and perigee full moons bring the highest (and lowest) tides of all. Each month, on the day of the full moon, the moon, Earth and sun are aligned, with Earth 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.
Today’s extra-close full moon accentuates these monthly (full moon) spring tides all the more.
If you live along a coastline, watch for high tides caused by the July 22 perigee full moon – or supermoon – over the next several days. Will the high tides cause flooding? Probably not, unless a strong weather system moves into the coastline where you are. Still, keep an eye on the weather, because storms do have a large potential to accentuate high spring tides.
Bottom line: The next supermoon will happen on July 22. A supermoon is a new or full moon that occurs with the moon at or near (within 90% of) its closest approach to Earth in a given orbit. That’s a generous definition, which is why there are so many supermoons! The July 22, 2013 moon is the third full supermoon this year.
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