Earth Moon Sun Vocabulary Sphere Round 3 dimensional

Earth, Moon, Sun Vocabulary

Sphere • Round 3 -dimensional object • The Earth is shaped like a sphere.

Axis • The imaginary vertical line that goes through the center of the Earth, the poles are at each end Axis • The Earth rotates on its axis.

Rotation • The spinning of earth on its axis, causes day and night to occur, one rotation takes about 1 day (or 24 hours) • The Earth makes one rotation every day.

Revolution • Earth’s yearly orbit around the sun, takes about 365 days • The Earth’s revolution takes about 1 year to completely go around the Sun.

Ellipse • An elongated, closed curve (smashed circle) • The Sun is at one end of the ellipse, not the center. The Earth travels around the sun in an ellipse.

Solstice • The day when the sun reaches its greatest distance, North (Summer) or South (Winter) of the equator. • Summer solstice is on June 21 st or 22 nd. • Winter solstice is on Dec 21 st or 22 nd. • The summer solstice is about the longest day of the year. The winter solstice is about the shortest day of the year.

Equinox • Occurs when the sun is directly above the equator. • Spring equinox is on Mar 20 th or 21 st. • Fall equinox is on Sept 22 nd or 23 rd. • During the equinox the number of daylight hours & nighttime hours is nearly equal all over the world.

Seasons on Earth

Moon Phase • Different forms that the moon takes in its appearance from earth • The moon phase depends on the relative positions of the moon, earth & sun.

New Moon • The moon is between the Earth & the sun, lighted ½ faces the sun, dark side faces Earth, see the moon as a dark circle • The new moon rises and sets with the sun.

Waxing • More of the illuminated (lighted by the sun) ½ of the moon can be seen each night, it seems to grow bigger • There are several different phases of waxing moons.

Full Moon • When all of the moon’s surface facing Earth reflects light from the sun • The full moon is when you can see the whole moon.

Waning • Less of the illuminated side of the moon can be seen each night, seems to be shrinking • Waning occurs after a full moon.

Solar Eclipse • Occurs when the moon moves directly between the Sun & Earth and casts its shadow over part of Earth. • Umbra is the darkest portion of the moon’s shadow = total solar eclipse • Penumbra is the lighter shadow on Earth’s surface = partial solar eclipse • Never look directly at the sun during a solar eclipse.

Full Solar Eclipse Partial Solar Eclipse http: //eclipse. gsfc. nasa. gov/SEdecade 2011. html

Lunar Eclipse • When Earth’s shadow falls on the moon. – Lunar eclipses begin when the moon moves into Earth’s penumbra. – When only a portion of moon moves into Earth’s umbra = partial eclipse – When the Earth completely blocks the light from the sun = total lunar eclipse • A total lunar eclipse can be seen by anyone on the nighttime side of Earth, where the moon is not hidden by clouds.

Total Lunar Eclipse Partial Lunar Eclipse http: //eclipse. gsfc. nasa. gov/LEdecade 2011. html

Maria • Dark colored, flat regions of the moon, formed when ancient lava filled craters on the moon’s surface • When you look at the moon, the dark spots you see might be maria.

Impact Basin / Crater • The depression left behind by objects striking the moon • The Meteor Crater in the state of Arizona was the first crater to be identified as an impact crater. • The South Pole- Aitken Basin is the largest and deepest impact basin in the solar system.

Moon Info Where does the moon’s light come from? • The moon’s light is a reflection of the sun’s light. Why do the sun & moon appear to be the same size? • Even though the moon is 400 times smaller than the sun it is 400 times closer to us than the sun. How does the moon move in the sky? • The moon rises in the East and sets in the West. It rises & sets about 1 hour later each day.