February’s Last-Quarter Moon: Why It’s Missing
February 11, 2016 - Supermoon
As we gawk during a first-quarter moon this week, we might consternation when a last-quarter moon will start this month. But there won’t be one, if we live in North or South America.
Take a conditions in eastern North America, that is in a Eastern Standard Time (EST) zone. The prior last-quarter moon was on Jan. 31 during 10:28 p.m. EST, and a subsequent one will be on Mar 1 during 6:11 p.m.
The arithmetic behind this is that a normal synodic lunar month — from new moon to new moon — is 29.53 days long, while Feb is possibly 28 or 29 days long. So it is possible, even in a jump year like 2016, to have one of a 4 categorical lunar phases tumble outward a calendar month of February. [Earth’s Moon Phases, Monthly Lunar Cycles (Infographic)]
Other tools of a world, such as Europe, had a last-quarter moon this month early on a morning of Feb. 1.
We make a large bitch about a “Blue Moon,” when there are dual full moons in a month, yet we don’t seem to notice when one of a lunar phases goes missing.
This raises a doubt of because a months change so many in their series of days: 28 or 29 in February, 30 in April, June, Sep and November, and 31 in a other 7 months. The problem is that the sun, moon and Earth don’t pierce to a balance of elementary arithmetic.
The lunar month consists of 29.530589 days, and a pleasant year (equinox to equinox) is 365.242190 days long. When a ancient astronomers attempted to erect a calendar with these weird numbers, they found that, literally, it did not compute.
Early astronomers divided a figure of a round into 360 degrees. This seems like a bizarre series to us with a decimal system, yet it done clarity with a series complement formed on 12. It also came tighten to a series of days in a year, yet not tighten enough. The year was divided into 12 months (a healthy in a base-12 series system) of 30 days any — yet that left a ungainly 5-and-a-bit-days remaining.
Mathematicians struggled with this problem for thousands of years, until finally a pope elect in 1582 came adult with a formidable yet superb solution, famous as a Gregorian calendar, after Pope Gregory XIII, who consecrated it.
In sequence to get a church’s feast days behind in proviso with a astronomical calendar, it was required to replace 11 days.
The Pope had a energy to make a new calendar in Catholic countries, yet there was a bit of grumbling about a 11 days, that went blank between Oct. 4 and Oct. 15, 1582. Just for fun, try entering Oct. 4, 1582, in a planetarium module like Starry Night, and afterwards allege to a subsequent day. You will find it is Oct. 15.
Naturally, England (along with a North American colonies) was one of a strongholds of a aged Julian calendar, and resisted adopting a popish Gregorian calendar until 1752. By that time, a calendar used by a English was off by 12 days, so that Sept. 2, 1752, was followed by Sept. 14, 1752, in England and a colonies.
To equivocate a missing-days problem, we now have a complement of 30- and 31-day months, with bad Feb being stranded with creation a whole thing fit. Thus, we have 29 days in Feb each 4 years, with a few exceptions to fine-tune a length of a year over a centuries. The outcome is that many months are a small longer than a lunar month, so they infrequently have dual full moons (or other double phases). And Feb infrequently ends adult blank a phase, as happens this year.
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