The Duration of Lunar and Solar Years A lunar year is made up of 354 days. A solar year is made up of 365 days. As a result of the differences in their definitions, there is an 11-day gap between one solar year and one lunar year. This temporal discrepancy is referred to as an epact. Because the orbit of the Moon around the Earth is not exactly circular, its distance from Earth varies over time. This leads to some fluctuations on the length of the lunar month - the period needed for the Moon to make one complete orbit around Earth. The average interval between full moons is 29.5 days, but this can range from 27.3 to 30.9 days.
Lunar Month vs Solar Year: How Does It Work? In order to compare the lengths of lunar months with solar years, we need to first understand how these terms are defined. A lunar month is the period between two consecutive new moons. It is divided into two equal parts called "waxing" and "waning" moons because the crescent shape of these objects changes over time. The term "lunar year" refers to the amount of time it takes for the Earth's shadow to pass over the face of the moon. This occurs once each lunar month and causes the temperature within Earth's shadow to drop significantly below zero degrees Celsius (32 degrees Fahrenheit).
A solar year, as opposed to a lunar year, consists of 12 months of 29–30 days each, for a total of 354–355 days. A lunar year has 13 months that are 29–30 days long, making it longer than 365 days. Therefore, a lunar year is about 11 days shorter than a solar year.
Lunar years were originally based on the time it took the moon to orbit Earth, which was about 29 days 5 hours 39 minutes 48 seconds. However, over time, scientists have discovered errors in the original calculation for the amount of time it takes the moon to orbit Earth, so they have revised the value used for lunar years over time. For example, before 1803, when the first national census was taken, the value used for lunar years was based on the time it took the moon to orbit at its minimum distance from Earth (about 379 miles), which was about 29 days 0 hours 56 minutes 48 seconds. But since then, scientists have found evidence that the moon is actually 14% farther away from Earth at its closest point, which would make its average distance more like 453 miles. Using this new estimate for lunar distance, the amount of time it takes the moon to orbit Earth increases by about 7 hours 43 minutes 16 seconds, which means that a lunar year now lasts about 30 days 23 hours 56 minutes 36 seconds instead of 29 days.
One lunar year is equivalent to one solar year plus 19 solar dates. Five lunar years equal five solar years. There are three solar months and two solar dates. Ten lunar years are equivalent to ten solar years. A year has six solar months and four solar dates. The length of a lunar year is equal to the length of a solar year. There are 11 solar months and 1 solar date. Every 29 or 30 years, the moon's orbit around the Earth brings it close enough to our planet for us to see it from time to time. When this happens, the moon will appear dimmer than usual because some of its light is blocked by Earth. This phenomenon is called "eclipse". During a total lunar eclipse, the Moon is completely covered by Earth's shadow. All direct sunlight is blocked out from directly reaching the Moon, so only light from the Sun as refracted through Earth's atmosphere reaches it. Most of this refracted light is at high altitudes where it forms a reddish hue on any objects facing towards Earth. These objects include all landforms on the Moon, but especially significant features such as craters and mountains. The color varies depending on how much dust is present in Earth's atmosphere at the time of the eclipse.
The Moon is also affected by other bodies in Earth's vicinity. The gravitational pull of Jupiter and Saturn cause an annual cycle of changes known as "librations". These movements are too small to see with the unaided eye but have been recorded by astronomers using very accurate instruments.
A completely lunar calendar is further distinguished from a lunisolar calendar, in which the lunar months are brought into sync with the solar year by some intercalation procedure. Because each lunation lasts around 291/2 days, the months of a lunar calendar often rotate between 29 and 30 days. Thus, there are only 12 lunar months in an annual cycle, whereas there are 13 solar months in a tropical year. Further, since the moon's orbit is not exactly circular but tends to be more elliptical, the length of its month varies over time.
Lunar calendars were used throughout much of history and still today in regions where the tropics are not close at hand - such as most of Asia and Africa. They are based on the observation that the moon causes certain events to happen every month: The tides rise and fall, plants grow and animals breed. By marking these events, a calendar can be constructed that tells us when to plant and harvest our crops and raise our animals.
The idea of using the moon as a clock dates back at least as far as 600 B.C., when the Greek philosopher Thales predicted two eclipses that had not yet taken place. He suggested that this could only happen once every 12 years, so he must have known about the lunar month. However, it was not until much later that anyone tried to make use of this knowledge.
One earth day lasts 24 hours, divided into 12 light hours and 12 dark hours. The lunar day, or the amount of time one side of the moon is exposed to the sun, lasts approximately 14 earth days, and the lunar night, or the amount of time one side of the moon is uncovered to the sun, lasts about 14 earth days as well. So, in summary, one lunar night is equal to two lunar days, and one lunar day is equal to three lunar nights.
The Moon is always turning over, so at any given moment there are half-lit and half-dark regions on its surface. These differ from region to region, but generally speaking the lit regions will be near the limb (outer edge) of the Moon i.e. they're not centered on the Moon's body, whereas the unlit regions will be inside the shadow cast by Earth.
Because the distance between the Sun and the Moon is very large, only the far side of the Moon experiences full darkness when viewed from Earth. Instead, both the near side and the far side experience a period of nighttime during which no part of them is illuminated by sunlight. This is called a "Lunar Night".
During a Lunar Night, the only parts of the Moon that are illuminated by sunlight are those near the center, where the angle between the Sun and the Moon is low.
A lunar month is 29.53 days long. So you're roughly 354 days after 12 lunar months. This is less than the 365 days required for the Earth to circle the Sun. It takes 33 years for the lunar year cycle to return to its initial place.
The moon has a very important role in determining when plants grow and animals breed. The amount of sunlight that reaches the moon changes how quickly it orbits around the earth, which in turn affects the earth's climate and organisms who live on land or in water. As the moon gets brighter, it heats up because more light energy is absorbed by the earth's atmosphere. This is one reason why spring comes later each year and winter arrives earlier.
The lunar year is also called the saros series. It starts with a new moon when earth is closest to the sun. After this first quarter moon, we can see almost all the way across the moon. Then gradually the moon moves away from earth until it is completely dark outside. At this point, we have reached full moon. Full moons occur when the moon is at its largest distance from earth. It will then begin to shrink again until it becomes new moon once more.
This whole cycle begins over again. So every 28 or 29 days we get another lunar eclipse! A lunar eclipse can only happen at full moon and somewhere within the shadow of a planet or large asteroid.