Fill in the Blanks Moon Phases Fill in the BlanksOnline version Learn about the moon's phases by filling in the blanks of this text! by Reading Readiness Center 1 disappeared phases opposite side sunlight third quarter moon Earth new moon full moon first quarter The has four main : , , , and . The first quarter is when the moon looks like a half circle . The full moon is when the moon looks like a big circle . The third quarter is when the moon looks like a different half circle . The new moon is when the moon looks like it has ! These phases happen because the moon is always moving around the , and the is shining on different parts of it . When the moon is between the Earth and the sun , we can't see it at all . That's the new moon . When the moon is on the of the Earth from the sun , we see it fully lit up , and that's the full moon . The other phases happen in between those two .