SOLAR SYSTEM MODELS

EARTH CENTERED SYSTEM DEVELOPED BY PTOLEMY

WAS ACCEPTED UNTIL THE 1960’S

SUN CENTERED SYSTEM DEVELOPED BY COPERNICUS

MODERN UNDERSTANDING OF THE STRUCTURE OF THE

UNIVERSE

GEOCENTRIC

HELIOCENTRIC

CELESTIAL OBJECTS- OBJECTS OBSERVED IN THE SKY DURING THE DAY OR NIGHT. (PLANETS, SUN, MOON, STARS…)

CONSTELLATION- A GROUP OF STARS THAT MAKE AN IDENTIFIABLE PATTERN IN THE SKY

A SPINNING ABOUT THE NORTH AND SOUTH AXIS

ROTATION

EVIDENCE:THE APPARENT DAILY COUNTER- CLOCKWISE MOTION OF CELESTIAL OBJECTS AROUND POLARIS (NORTH STAR) IS BECAUSE OF EARTH’S ROTATION TOWARD THE EAST. (RATE = 15° PER HOUR)

SOLAR DAY- THE AMOUNT OF TIME REQUIRED FOR THE EARTH TO ROTATE FROM ONE NOON TO THE NEXT.

15° X 24 HOURS = 360°

HORIZONTAL DEFLECTION UNDERGONE BY ALL MOVING MATERIALS ON THE EARTH’S SURFACE

CORIOLUS EFFECT

NORTHERN HEMISPHER - DEFLECTED TO THE RIGHT

(CLOCKWISE)

SOUTHERN HEMISPHERE - DEFLECTED TO THE LEFT

(COUNTER CLOCKWISE)

LET’S SHOOT SOME CANNONS!!

FOUCAULT PENDULUM

AN EXPERIMENT TO DEMONSTRATE THE ROTATION OF THE EARTH

A SLIGHTLY ELLIPTICAL ORBIT AROUND THE SUN (COUNTER CLOCKWISE)

365.25 DAYS FOR ONE REVOLUTION

REVOLUTION

PERIHELION - SUN IS THE LARGEST, OCCURS IN THE N.H. WINTER (SHORTEST DISTANCE BETWEEN THE EARTH & SUN)

APHELION - SMALLEST, OCCURS IN THE N.H. SUMMER (LARGEST DISTANCE BETWEEN THE EARTH & SUN)

EVIDENCE:

SEASONAL CHANGE OF THE CONSTELLATIONS

THE SOLAR DIAMETER VARIES IN A CYCLIC PATTERN

SEASONS

THE EARTH’S TILT IS

LOCAL NOON – WHEN THE SUN REACHES ITS MAXIMUM ALTITUDE

ZENITH – THE POINT DIRECTLY OVERHEAD

**THE SUN’S RAYS CAN ONLY BE DIRECTLY OVERHEAD AT SOLAR NOON BETWEEN THE TROPICS

(23.5° N OR S OF THE EQUATOR)

23.5°

PARALLELISM OF THE EARTH’S AXIS – THE EARTH AXIS REMAINS PARALLEL THROUGHOUT ITS REVOLUTION AROUND THE SUN.

EQUINOX – THE SUN IS IN THE ZENITH POSITION AT THE EQUATOR (MARCH 21ST AND SEPT. 23RD)

12 HOURS OF BOTH DAYLIGHT AND DARKNESS

SUMMER SOLSTICE – THE SUN IS IN THE ZENITH POSITION AT THE TROPIC OF CANCER (JUNE 21ST )

LONGEST DAYLIGHT OF THE YEAR IN THE NORTHERN HEMISPHERE

WINTER SOLSTICE – THE SUN IS IN THE ZENITH POSITION AT THE TROPIC OF CAPRICORN (DEC. 21ST)

SHORTEST DAYLIGHT OF THE YEAR IN THE NORTHERN HEMISPHERE

Summer

Winter