![]() The moon is above the horizon for 12 hours a day, but its appearance may not always coincide with daylight hours. "That day the sun sets and then the moon rises and the other way round, so that's the only day where it's not up there at the same time." "The only day that it isn't in the sky with the sun for some time is the full moon," Guinan said. When it is near the full moon, it is only visible at night, because the moon rises at sunset and sets at sunrise. ![]() Near the new moon phase, it is too close to the sun to be seen. The other five days occur around the new moon phase and the full moon. The moon is visible during daylight for an average of 25 days out of the month throughout the year. However, the moon's visibility during daylight is also influenced by other factors, including the seasons, the current phase of the moon and how clear the sky is on a given day. Since the moon is closer to Earth than stars are, its surface brightness is greater than the surface brightness of the sky, Guinan explained, meaning we can easily see it shining during daylight. ![]() The scattered light from the sun is so bright in our sky that it often overwhelms the starlight during the day, but not always the moon's reflected light.Īstronomers use surface brightness as a way of quantifying the apparent brightness of objects in the sky, such as galaxies or nebulae, by measuring the amount of light they emit across an area of the night sky, as observed from Earth. ![]() An illustration of the different lunar phases (Image credit: Shutterstock)Īccording to Guinan, the stars that are visible from Earth are a million billion times less bright than the light from the sun, and millions of times fainter than that of the moon. ![]()
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