Phases of the Moon
By: Sophie Lawrence, Ph.D.
The First and Third Quarter
All moon phases are different, but some have more in common than others. Take the First and Third Quarter Moons. Both have about 50% of the total amount we can see showing, which is why most younger children call them a "Half Moon". In relation to the positions during both phases, they form at a 90 degree angle between the Earth, Sun, and Moon.
the moon and me
My Time on the ISS Changed My Moon-Viewing Perspective.
When an astronaut is viewing the moon from the International Space Station, they're in a different position than those astronomers on Earth. From the ISS, you can see the sun, moon, and the Earth all at once. You're orbiting the Earth, just like the moon. Therefore, you see all sides of the moon, which makes it look like there aren't any moon phases. From Earth, you can't even see the sun and the moon at the same time, and since the moon is orbiting around you, the phases "occur" like always.