Sources of Light
Stars
Stars produce their own light through nuclear fusion. This process produces energy as well. Two atomic nuclei collide to form a larger nucleus. Hydrogen atoms join to form helium. When the hydrogen converts to helium, there is a small difference in mass. That small amount of mass is changed into energy.
Moon Phases
The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.
Stars produce their own light through nuclear fusion. This process produces energy as well. Two atomic nuclei collide to form a larger nucleus. Hydrogen atoms join to form helium. When the hydrogen converts to helium, there is a small difference in mass. That small amount of mass is changed into energy.
Moon Phases
The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth.
Solar/Lunar Eclipse
When the moon's shadow hits Earth or Earth's shadow hits the moon, an eclipse occurs. Either a solar or lunar eclipse will occur. A solar eclipse happens when a new moon lies between Earth and the sun, so that it blocks the sunlight. A lunar eclipse is when the moon is on the opposite side of the sun, and the Earth blocks sunlight from illuminating the moon.
Solar Eclipse Lunar Eclipse
When the moon's shadow hits Earth or Earth's shadow hits the moon, an eclipse occurs. Either a solar or lunar eclipse will occur. A solar eclipse happens when a new moon lies between Earth and the sun, so that it blocks the sunlight. A lunar eclipse is when the moon is on the opposite side of the sun, and the Earth blocks sunlight from illuminating the moon.
Solar Eclipse Lunar Eclipse