text: The Moon The Moon appears as a grey disc in the sky with cratering visible to the naked eye. It spans, depending on its exact location, 29–33 arcminutes – which is about the size of a thumbnail at arm's length, and is readily identified. Over 29.53 days on average, the moon goes through a full cycle of lunar phases. People can generally identify phases within a few days by looking at the Moon. Unlike stars and most planets, the light reflected from the Moon is bright enough to be seen during the day.
  Some of the most spectacular moons come during the full moon phase near sunset or sunrise. The Moon on the horizon benefits from the Moon illusion which makes it appear larger. The Sun's light reflected from the Moon traveling through the atmosphere also appears to color the Moon orange and/or red.
  Comets
  Comets come to the night sky only rarely. Comets are illuminated by the Sun, and their tails extend away from the Sun. A comet with a visible tail is quite unusual – a great comet appears about once a decade. They tend to be visible only shortly before sunrise or after sunset because those are the times they are close enough to the Sun to show a tail.