The phenomenon was explained satisfactorily by Isaac Newton, attributing it to the gravitational attraction exerted by the moon and the sun. Tides are periodic changes in sea level known since ancient times. Do the phases of the moon affect the tides? Approximately every day the moon delays its rising (and setting) by about 50 minutes, and this explains why the waxing becomes better visible a few days after the new moon as the elongation from the sun increases and further and further eastward.Īccording to this reasoning, the maximum delay is at the new moon (24 hours) but also the minimum (0 hours) with the start of a new cycle. Moving towards the east, our satellite rises later every day, and this is the reason why we see it in different positions at the same time. The production of the phases depends on the Earth-moon-sun geometry and on the revolution motion of the moon around the Earth. How do the phases of the moon affect moonrise and moonset? However, this is a very simplified description since the lunar motion is actually very complex, and the perspective with which we see the near side constantly changes, getting to see almost 60% of the lunar surface thanks to the phenomenon called libration. However, it was difficult to establish the exact moment of the new moon, therefore, many ancient civilizations started the lunar month with the appearance of the first crescent after sunset. Thanks to the regular repetition of these moments, since ancient times, the lunar phases have been the basis of the lunisolar calendar. In the new moon phase, this percentage is 0% and becomes 100% at Full moon, about 14 days later. The substantial difference is in the illumination percentage of the side facing the Earth. What is the difference between Full Moon and New Moon? They are in order, New Moon, First Quarter, Full Moon, and Last Quarter. Although these lighting variations are gradual, traditionally, only four moments are identified, which are also useful for regulating the ancient calendars. As it orbits Earth, the moon will show different illuminated parts based on the angle to the sun and hence the phases of a lunation. On a daily basis, the moon appears to move eastward in the sky by 12°, and this determines different angles of its illumination by the sun. This means that one lunar rotation on its axis corresponds to the time of revolution around Earth, equal to 29.5 days. Of the moon, we always see a hemisphere and a little more because its rotation is synchronous and blocked by the tide. To better understand how it works, let us, first of all, remember that the moon does not emit its own light but reflects that of the sun and partly that reflected by the Earth–phenomenon of ashen light. The phases of the moon are a consequence of its motion around Earth in relation to the geometry assumed with respect to the sun. Giuseppe Donatiello is an Italian amateur astronomer, astrophotographer, and author who is known for his discovery of six nearby dwarf galaxies and several planetary nebulas. Usually, the moon passes above or below the sun from our vantage point, but occasionally it passes right in front of the sun, and we get a solar eclipse. Now, the moon is between Earth and the sun. Waning crescent: Less than half of the moon's face appears to be getting sunlight, and the amount is decreasing.įinally, the moon is back to its new moon starting position. The sun's light is now shining on the other half of the visible face of the moon. Last quarter: The moon has moved another quarter of the way around Earth, to the third quarter position. Waning gibbous: More than half of the moon's face appears to be getting sunlight, but the amount is decreasing. When they do, we have a lunar eclipse as Earth's shadow crosses the moon's face. The sun, Earth and the moon are aligned, but because the moon’s orbit is not exactly in the same plane as Earth’s orbit around the sun, they rarely form a perfect line. More than half of the moon's face appears to be getting sunlight.įull moon: The moon is 180 degrees away from the sun and is as close as it can be to being fully illuminated by the sun from our perspective. Waxing gibbous: The area of illumination continues to increase. See the moon phases, and the difference between a waxing and waning crescent or gibbous moon, in this infographic about the lunar cycle each month. Moon phases 2023 with times (Eastern Time) New Moon
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