Are the phases of the moon created by the earth’s shadow? And, if so, how can i see the moon in its phase during the daytime?
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It’s helpful to imagine a simple model to understand moon phases: it just takes two objects (balls are best) and a lamp.
If you place ball E (for earth) adjacent to ball M (moon) and shine the lamp from a few feet away, you’ll see a different shadow (phase) of M than if you place M between E and the lamp, or if you place M to the other side of E, or if you place M behind E.
Here’s a nice illustration of an even simpler way:
No the moon’s phases are due to the fact that only half of the moon is lit up by the sun at any given moment. If the Earth is approximately between the sun and the moon the we are seeing the lit up side which is a full moon. Then as the moon orbits the earth we see less and less of the lit up side until the moon is approximately between the earth and the sun, at which point there is a new moon.
If all three are precisely in line then we get an eclipse, but this doesn’t happen every cycle because the orbits are not quite aligned.
Exactly half of the moon is lit by the sun at all times, just like the earth is. The “phases” of the moon are how much of the lit side we can see.
The moon orbits the earth once a month, so for part of its orbit it’s on the same side of the earth as the sun (earth’s daytime), and for part of the orbit it’s on the opposite side of the sun (earth’s nighttime). If it’s on the same side as the sun, then obviously the sunlit half of the moon is the half that’s facing away from us (new moon). If it’s on the opposite side as the sun, then the sunlit half of the moon is the half that’s facing toward us (full moon). And if it’s off to the side, then we see part of the sunlit side, so the first and third quarter, and waxing/waning crescents.
The moon’s orbit is tilted with respect to the earth’s orbit around the sun, so it’s very rare that the earth’s shadow is cast on the moon. These rare occasions are called lunar eclipses.
It’s helpful to imagine a simple model to understand moon phases: it just takes two objects (balls are best) and a lamp.
If you place ball E (for earth) adjacent to ball M (moon) and shine the lamp from a few feet away, you’ll see a different shadow (phase) of M than if you place M between E and the lamp, or if you place M to the other side of E, or if you place M behind E.
Here’s a nice illustration of an even simpler way:
Exactly half of the moon is lit by the sun at all times, just like the earth is. The “phases” of the moon are how much of the lit side we can see.
The moon orbits the earth once a month, so for part of its orbit it’s on the same side of the earth as the sun (earth’s daytime), and for part of the orbit it’s on the opposite side of the sun (earth’s nighttime). If it’s on the same side as the sun, then obviously the sunlit half of the moon is the half that’s facing away from us (new moon). If it’s on the opposite side as the sun, then the sunlit half of the moon is the half that’s facing toward us (full moon). And if it’s off to the side, then we see part of the sunlit side, so the first and third quarter, and waxing/waning crescents.
The moon’s orbit is tilted with respect to the earth’s orbit around the sun, so it’s very rare that the earth’s shadow is cast on the moon. These rare occasions are called lunar eclipses.
The earth spins on it’s own axis creating night and day, and as the moon orbits around the earth the sun is relatively static. So a good analogy would be to imagine you (the earth) standing in a room with a light on (the sun) while you hold a basketball (the moon) at arms length. if you face away from the light (night time) and hold the basketball in front of you, it will be fully lit (full moon). But if you hold the basketball to either side of you, as you still face away from the light, the basketball will only be half lit (half full moon) and half shadow. And if you imagine holding the basketball behind you, in between you and the light, you will only see the shadow side of the ball (a new moon).
The earth spins on it’s own axis creating night and day, and as the moon orbits around the earth the sun is relatively static. So a good analogy would be to imagine you (the earth) standing in a room with a light on (the sun) while you hold a basketball (the moon) at arms length. if you face away from the light (night time) and hold the basketball in front of you, it will be fully lit (full moon). But if you hold the basketball to either side of you, as you still face away from the light, the basketball will only be half lit (half full moon) and half shadow. And if you imagine holding the basketball behind you, in between you and the light, you will only see the shadow side of the ball (a new moon).
The earth spins on it’s own axis creating night and day, and as the moon orbits around the earth the sun is relatively static. So a good analogy would be to imagine you (the earth) standing in a room with a light on (the sun) while you hold a basketball (the moon) at arms length. if you face away from the light (night time) and hold the basketball in front of you, it will be fully lit (full moon). But if you hold the basketball to either side of you, as you still face away from the light, the basketball will only be half lit (half full moon) and half shadow. And if you imagine holding the basketball behind you, in between you and the light, you will only see the shadow side of the ball (a new moon).
Turn on a lamp in a darkened room and grab any small spherical object.
With the lamp behind you, hold the object out in front of you, but away from your own shadow. This is a full moon at midnight.
Still holding the object in front of you, turn to your left. This is a last quarter moon at sunrise.
Turn left again. Hold the object so it doesn’t quite block the lamp’s light. This is a new moon at noon.
Turn left again. This is a first quarter moon at sunset.
Now, if you could find a way to suspend the object in each of these positions so you don’t have to hold it yourself, you can turn around to the left in place to simulate how the sun and moon cross the sky as the Earth turns.
The relative angle between the sun and moon as the moon orbits around the Earth causes the moon’s phase change. The darkened portion is simply the half of the moon which faces away from the sun.
Turn on a lamp in a darkened room and grab any small spherical object.
With the lamp behind you, hold the object out in front of you, but away from your own shadow. This is a full moon at midnight.
Still holding the object in front of you, turn to your left. This is a last quarter moon at sunrise.
Turn left again. Hold the object so it doesn’t quite block the lamp’s light. This is a new moon at noon.
Turn left again. This is a first quarter moon at sunset.
Now, if you could find a way to suspend the object in each of these positions so you don’t have to hold it yourself, you can turn around to the left in place to simulate how the sun and moon cross the sky as the Earth turns.
The relative angle between the sun and moon as the moon orbits around the Earth causes the moon’s phase change. The darkened portion is simply the half of the moon which faces away from the sun.
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