HOW DO THE SUN & MOON AFFECT EARTH? Eclipses Day & Night Moon Phases Changing of the seasons

WHAT IS AN ECLIPSE? When 1 object in space comes between the Sun & a 3rd object, and cast a shadow on that object

HOW DOES IT HAPPEN? When the moon’s shadow hits Earth or Earth’s shadow hits the moon

TWO TYPES OF SHADOWS: Penumbra Umbra

PENUMBRA Large shadow

UMBRA Small shadow

TWO TYPES OF ECLIPSES: Solar Lunar

SOLAR ECLIPSE Moon passes between the Sun & Earth A new moon

PARTIAL SOLAR ECLIPSE Moon’s penumbra casts a larger shadow Part of the Sun is visible

TOTAL SOLAR ECLIPSE Moon’s umbra blocks all sunlight from reaching Earth Sky is dark

LUNAR ECLIPSE Occurs at a full moon when Earth is directly between the moon & the Sun

PARTIAL LUNAR ECLIPSE The moon, sun, & Earth are not quite in line The moon passes through part of the umbra

TOTAL LUNAR ECLIPSE The moon is in the Earth’s umbra This can be seen anywhere on Earth

WHAT CAUSES DAY & NIGHT? The spinning of Earth on its axis Each rotation takes 24 hours

WHY DOES THE MOON CHANGE SHAPE EACH MONTH? The moon goes through a set of “phases” each time the moon revolves around Earth or about a month

MOON’S REVOLUTION The moon revolves/orbits around Earth 1 revolution=27.3 days

MOON’S ROTATION The moon rotates on its own axis just like Earth 1 rotation=27.3 days

MOON’S PHASES A “day” and a “year” are the same length on the moon

WHAT CAUSES THESE PHASES? Changes in the positions of the Sun, Earth, and Moon The moon’s phases depends on how much of the sunlit side of the moon faces Earth

DOES THE MOON PRODUCE ITS OWN LIGHT? No! It reflects light from the Sun

EXPLORING THE MOON’S PHASES

WANING VS. WAXING Waning is the fading of sunlight Waxing is the adding of sunlight

NEW MOON

CRESCENT

GIBBOUS

FULL MOON

HOW DOES THE SUN AFFECT OUR SEASONS? Earth has an elliptical orbit The Sun is not centered in the ellipse The distance between the Sun & Earth changes during the year, but this does not affect our seasons Fact: When Earth is closest to the sun the northern hemisphere is experiencing winter

FALL, WINTER, SPRING…OH MY! Earth has different seasons because its axis is tilted at 23.5 degrees Earth revolves around the Sun 1 revolution/orbit=1 year

SOLSTICE The noon sun is directly overhead at 23.5° Winter Summer

WINTER SOLSTICE Begins December 21st Shortest day of the year in the Northern Hemisphere

SUMMER SOLSTICE Begins June 21st Longest day of the year in the Northern Hemisphere

EQUINOX The noon sun is directly over the equator Vernal Autumnal

VERNAL EQUINOX Begins March 21st Marks the beginning of spring in the Northern Hemisphere

AUTUMNAL EQUINOX Begins September 23rd Marks the beginning of fall in the Northern Hemisphere

WHAT IS ASTRONOMY? Study of the moon, stars, & other objects in space