SEASONS TEST

TILT OF EARTH’S AXIS

VERNAL EQUINOX

• March 20, 2015, is a date that most of us recognize as symbolic of changing seasons. As we welcome spring, people south of the equator are actually gearing up for the cooler temperatures of autumn.

• Translated literally, equinox means "equal night." Because the Sun is positioned above the equator, day and night are about equal in length all over the world during the equinoxes

DAY AND NIGHT-earth is rotating on its axis!

EARTHS SEASONS

SEASONS

• IN THE PREVIOUS SLIDE, WHO HAS • LONGER DAYS, • SHORTER DAYS• WARMER WEATHER• COOLER WEATHER

REVOLUTION

• ROTATION IN 24 HOURS = 360 DEGREES• ROTATION IN 360/24=15 DEGREES PER HOUR.

HOW MANY DEGREES IN 4 HOURS?

WHY IS THERE A LEAP YEAR?

• 365.25 DAYS FOR ONE COMPLETE REVOLUTION

• EVERY FOURTH YEAR WE ADD A DAY TO ACCOUNT FOR THE .25….LEAP YEAR A CALENDAR DAY IS ADDED IN FEBRUARY

• HOW LONG WOULD IT TAKE THE EARTH TO COMPLETE 5 ORBITS AROUND THE SUN???

• 365.25 x 5 =______

SUNRISE SUNSET

• EARTH ROTATES FROM WEST TO EAST, THEREFORE WE SEE THE SUN RISE IN THE EAST AND SET IN THE WEST.

EQUINOXES

• IN THE SPRING AND THE FALL, NEITHER HEMISPHERE IS TILTED TOWARD OR AWAY FROM THE SUN, BOTH RECEIVE AN “EQUAL” AMOUNT OF SUNLIGHT

• SUNS VERTICAL RAYS STRIKE THE EQUATOR

MOON- the phase depends on how much of the sunlit side faces earth

SUMMER SOLSTICE

CONSTELLATIONS• As the World Turns• In our time, scientists (and most people!) know that the constellations seem to

move across the sky because the earth rotates on its axis. What, you may ask, does the turning of the earth have to do with the constellations' motion across the sky? The answer is that the earth moves in a way that makes it look as if the constellations are moving. It is a case of apparent motion. In the case of the earth and the constellations the earth rotates, with us on it, from west to east. The constellations appear to move from east to west, moving "backwards" from the real rotation of the earth. Actually, instead of saying the constellations rise we should say that the earth has rotated so that we can see different constellations. Then, as the earth continues to rotate the constellations apparently move across the sky. We now know that it is us, on earth, that have moved. As the night progresses constellations that are near or below the ecliptic "set" in the west, we know that the part of the earth we are standing on has turned so that the Earth is blocking our view of the stars that have "set".

TIME

TIME

• Time at point A is 12 noon. What is time at B C and D?

• _____________A

Day/Night

• Label N S E and W• Half is in darkness (night) and half in

daylight(light)---how does this look?• The middle would be in dusk (near sunset)• Earth rotates from w to e…what will happen?