Eventually, the Moon arrives at position E in our figure, where it and the Sun are opposite each other in the sky. The side of the Moon turned toward the Sun is also turned toward Earth, and we have the full phase. When the Moon is full, it is opposite the Sun in the sky. The Moon does the opposite of what the Sun does, rising at sunset and setting at sunrise.
Its illumination throughout the night helps lovers on a romantic stroll and students finding their way back to their dorms after a long night in the library or an off-campus party.
And when is the full moon highest in the sky and most noticeable? At midnight, a time made famous in generations of horror novels and films.
Note how the behavior of a vampire like Dracula parallels the behavior of the full Moon: Dracula rises at sunset, does his worst mischief at midnight, and must be back down in his coffin by sunrise. For example, homicides occur at the same rate during the new moon or the crescent moon as during the full moon.
Most investigators believe that the real story is not that more crazy behavior happens on nights with a full moon, but rather that we are more likely to notice or remember such behavior with the aid of a bright celestial light that is up all night long. During the two weeks following the full moon, the Moon goes through the same phases again in reverse order points F, G, and H in Figure 1, returning to new phase after about About a week after the full moon, for example, the Moon is at third quarter , meaning that it is three-quarters of the way around not that it is three-quarters illuminated—in fact, half of the visible side of the Moon is again dark.
At this phase, the Moon is now rising around midnight and setting around noon. Note that there is one thing quite misleading about Figure 1. The Moon is actually 30 Earth-diameters away from us; Science and the Universe: A Brief Tour contains a diagram that shows the two objects to scale. The week seems independent of celestial motions, although its length may have been based on the time between quarter phases of the Moon.
In English, we can easily recognize the names Sun-day Sunday , Moon-day Monday , and Saturn-day Saturday , but the other days are named after the Norse equivalents of the Roman gods that gave their names to the planets.
In languages more directly related to Latin, the correspondences are clearer. There is no reason that the week has to have seven days rather than five or eight. The time interval in which the phases repeat—say, from full to full—is the solar month , The Moon must make more than a complete turn around the moving Earth to get back to the same phase with respect to the Sun. As we saw, the Moon changes its position on the celestial sphere rather rapidly: even during a single evening, the Moon creeps visibly eastward among the stars, traveling its own width in a little less than 1 hour.
The delay in moonrise from one day to the next caused by this eastward motion averages about 50 minutes. The most recent "blue Moon" occurred in August On average, there's a Blue Moon about every 33 months.
Blue Moons are rare because the Moon is full every 29 and a half days, so the timing has to be just right to squeeze two full Moons into a calendar month. The timing has to be really precise to fit two Blue Moons into a single year.
It can only happen on either side of February, whose day span is short enough time span to have NO full Moons during the month. The term "blue Moon" has not always been used this way, however. While the exact origin of the phrase remains unclear, it does in fact refer to a rare blue coloring of the Moon caused by high-altitude dust particles. Most sources credit this unusual event, occurring only "once in a blue moon," as the true progenitor of the colorful phrase.
The Moon always shows us the same face because Earth's gravity has slowed down the Moon's rotational speed. The Moon takes as much time to rotate once on its axis as it takes to complete one orbit of Earth. Both are about In other words, the Moon rotates enough each day to compensate for the angle it sweeps out in its orbit around Earth. Gravitational forces between Earth and the Moon drain the pair of their rotational energy. We see the effect of the Moon in the ocean tides.
Likewise, Earth's gravity creates a detectable bulge -- a foot land tide -- on the Moon. Eons from now, the same sides of Earth and Moon may forever face each other, as if dancing hand in hand, though the Sun may balloon into a red giant, destroying Earth and the Moon, before this happens. Astronomers refer to the crescent and gibbous phases as intermediate phases.
The phases of the Moon are connected to the position of the Moon in relation to the Sun. While the new moon is dictated by the close proximity of the Sun to the Moon, the full moon occurs when they are at opposite positions in the sky. The first and last quarters happen when the Moon has traveled one-and three-quarters way around its orbit.
As the phase cycles of the Moon are almost always shorter than a full calendar month, the phase of moon that occurs at the start of the month usually occurs again before the end of the month.
As a result, every 2. The colloquial term for this phenomenon is the "Blue Moon. The Islamic culture marks the beginning of the month by the first appearance of the waxing crescent moon. In some cultures, it is a taboo to see the new moon through glass. Updated April 21, The Explanation of Phases of the Moon. How to Find the Moon Phases.
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