Our Earth, Moon, and Sun ASTRONOMY
BIG IDEAS What causes the phases of the moon? Compare the causes of solar and lunar eclipses. Explain what causes the tides.
phases lunar solar eclipse gibbous crescent penumbra corona neap tide spring tide umbra corona WORD ATTACK
WHAT CAUSES THE PHASES OF THE MOON? The phase of the moon you see depends on how much of the sunlit side of the moon faces Earth. The moon revolves around Earth in the same amount of time the moon takes to rotate on its axis. As a result, the near side of the moon always faces Earth.
Current Moon Phase
VOCABULARY Umbra – darkest part of the cone- shaped shadow Penumbra – larger part of the cone- shaped shadow that is less dark
WHAT IS AN ECLIPSE? An eclipse occurs when an object in space comes between the sun and a third object, and casts a shadow on that object. There are two types of eclipses: Solar eclipses Lunar eclipses
Earth is directly between the moon and the sun. Earth blocks sunlight from reaching the moon. Occurs during a full moon. The moon passes between Earth and the sun. The moon blocks sunlight from reaching Earth. Occurs during a new moon. COMPARE THE CAUSES OF SOLAR AND LUNAR ECLIPSES. Solar Eclipse Lunar Eclipse
TOTAL SOLAR ECLIPSE People within the umbra of the moon’s shadow experience a total solar eclipse The sky is dark They can see the stars They can see the solar corona The moon’s orbit is tilted 5º with respect to Earth’s orbit. So the moon rarely goes directly between Earth and the sun.
PARTIAL SOLAR ECLIPSE People in the penumbra see only a partial eclipse meaning part of the sun remains visible Never look directly at the sun, not even when standing in the moon’s shadow Eclipses of the sun should only be viewed through specially prepared viewing devices
VOCABULARY What is the Umbra? What is the Penumbra?
UMBRA AND PENUMBRA
TOTAL LUNAR ECLIPSE The moon is in Earth’s umbra Can be seen anywhere on earth that the moon is visible
PARTIAL LUNAR ECLIPSE The moon passes partly into the umbra of Earth’s shadow Earth, the moon, and the sun are not quite in line The edge of the shadow appears blurry A partial lunar eclipse can be viewed for two or three hours