Today – January 30, 2014 – gives us the second of two new moons to occur in a single calendar month. Some are calling it a Black Moon. It’s also a supermoon, the second of this month. The first new supermoon of January came on January 1. A single calendar month won’t harbor two supermoons again until January 2018. Will you see it? No. But it’ll affect the tides.
Who coined the term “supermoon,” and what is it? The name supermoon doesn’t come from astronomy, but we like it. It’s the name for a new or full moon at its closest to Earth. We used to call these moons perigee new moons, or perigee full moons. Compared to those names, supermoon is better.
An astrologer, Richard Nolle, is credited for coining the term supermoon, and his definition is very generous. That’s why there are so many supermoons. He defines it as “. . . a new or full moon which occurs with the moon at or near (within 90% of) its closest approach to Earth . . .” By this definition, the new moon or full moon has to come within 361,863 kilometers (224,851 miles) of our planet, as measured from the centers of the moon and Earth. Therefore, the year 2014 gives us a total of five supermoons: two January new moons, and the full moons of July, August and September.
When is 2014’s closest supermoon? The full moon on August 10, 2014, will showcase the closest supermoon of the year (356,896 kilometers or 221,765 miles). However, the new moons on January 1 and January 30 are not all that far behind, featuring the year’s second-closest and third-closest supermoons, respectively. On January 1, the moon turned new less than 10 hours before reaching lunar perigee – the moon’s closest point to Earth in its orbit. On January 30, the moon turns new around 12 hours after lunar perigee.
Incidentally, the full moon on January 16, 2014, came to pass only a few hours after the moon reached lunar apogee – the moon’s most distant point from Earth for the month (406,532 kilometers or 252,607 miles). So two weeks after the year’s nearest new moon on January 1, it was the year’s farthest and smallest full moon on January 16, 2014. Then it’s the year’s second-closest new moon on January 30.
Will I be able to see the January 30 supermoon? No. Don’t expect to see the new moon on January 30. At the vicinity of new moon, the moon hides in the glare of the sun all day long, and pretty much rises with the sun at sunrise and sets with the sun at sunset. However, if you were on the moon, looking at Earth, you’d see a full Earth.
Spring tides accompany the January 30 supermoon. Will the tides be larger than usual? Yes, all new moons (and full moons) team up with the sun to usher in larger-than-usual tides, but perigee new moons (or perigee full 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.
The January 1 and 30 extra-close new moons accentuate the spring tide, to give rise to what’s called a perigean spring tide. If you live along an ocean coastline, watch for high tides caused by the two January 2014 new moons – or supermoons. Will these high tides cause flooding? Probably not, unless a strong weather system accompanies the perigean spring tide. Still, keep an eye on the weather, because storms do have a large potential to accentuate perigean spring tides.
Bottom line: What a super way to start the New Year, with the close alignment of the new moon and perigee ushering in the supermoons of January 1 and January 30, 2014! Wow!