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The absence of evidence is not the evidence of absence. - Carl Sagan -. THE MOON (LUNA) THE MOON ORBITS THE EARTH AT AN AVERAGE DISTANCE OF 382,000 KM OR 229,000 MILES. THIS DISTANCE IS INCREASING BY ABOUT 38 mm PER YEAR.
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The absence of evidence is not the evidence of absence. - Carl Sagan -
THE MOON (LUNA) THE MOON ORBITS THE EARTH AT AN AVERAGE DISTANCE OF 382,000 KM OR 229,000 MILES. THIS DISTANCE IS INCREASING BY ABOUT 38 mm PER YEAR.
THE DIAMETER OF THE MOON IS 3,474 KM OR 2,084 MILES – ABOUT ¼ OF THE EARTH’S DIA. THE GRAVITY ON THE MOON’S SURFACE IS 17% OF THAT OF EARTH’S. BETWEEN 1969 AND 1972, THE U.S. MADE SIX LANDINGS ON THE MOON.
IT TAKES 29.5 DAYS FOR THE MOON TO CIRCLE THE EARTH. ITS PERIOD OF ROTATION IS ALSO 29.5 DAYS, SO WE ONLY SEE ONE SIDE OF THE MOON. THE MOON REFLECTS THE LIGHT FROM THE SUN, SO WE ARE SEEING ONLY THAT PART OF THE MOON THAT IS LIT BY THE SUN. THIS RESULTS IN WHAT WE CALL PHASES OF THE MOON.
THE DARK PLAINS ARE CALLED MARIA. THE LIGHTER COLORED REGIONS ARE HIGHLANDS. NEAR SIDE FAR SIDE
ONCE IN A BLUE MOON – WHAT’S A BLUE MOON? THE MOON ORBITS THE EARTH ONCE EVERY 29.5 DAYS. THE AVERAGE MONTH IS 30.5 DAYS LONG. IT IS NOT VERY LIKELY TO HAVE TWO FULL MOONS IN THE SAME MONTH. THAT EVENT HAPPENS EVERY 2 ½ YEARS. SO, A BLUE MOON IS THE SECOND FULL MOON IN A MONTH. THE NEXT BLUE MOONS WILL BE ON JULY 31, 2015 AND AUGUST 20-21, 2013.
The Fission Theory: The Moon was once part of the Earth and somehow separated from the Earth early in the history of the Solar System. The present Pacific Ocean basin is the most popular site for the part of the Earth from which the Moon came. The Capture Theory: The Moon was formed somewhere else, and was later captured by the gravitational field of the Earth. The Condensation Theory: The Moon and the Earth condensed together from the original nebula that formed the Solar System.
The Colliding Planetesimals Theory: The interaction of earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the Solar System led to their breakup. The Moon condensed from this debris. The Ejected Ring Theory: A planetesimal the size of Mars struck the earth, ejecting large volumes of matter. A disk of orbiting material was formed, and this matter eventually condensed to form the Moon in orbit around the Earth. TAKEN FROM: http://csep10.phys.utk.edu/astr161/lect/moon/moon_formation.html
THE LAST THEORY IS THE MOST POPULAR. • THE EARTH’S CRUST AND THE MOON’S SURFACE HAVE SIMILAR COMPOSITIONS. • THE EARTH HAS A LARGER THAN EXPECTED IRON CORE, AND THE MOON HAS NONE. • THE RELATIVE SIZE OF OUR MOON IS LARGE COMPARED TO THE RELATIVE SIZES OF THE MOONS OF OTHER PLANETS.
THE MOON, AND TO A LESSER EXTENT, THE SUN ARE RESPONSIBLE FOR TIDES ON EARTH. THE GRAVITATIONAL PULL OF THE MOON PULLS THE OCEANS TOWARDS IT ON THE SIDE FACING THE MOON. ON THE OPPOSITE SIDE, YOU CAN THINK OF THE EARTH BEING PULLED AWAY FROM THE WATER.
SPRING TIDES ARE THE HIGHEST. THEY OCCUR WHEN THE EARTH AND SUN ARE ALIGNED WITH THE EARTH. NEAP TIDES ARE THE LOWEST, AND THEY OCCUR WHEN THE SUN AND MOON ARE AT RIGHT ANGLES WITH RESPECT TO THE EARTH.
OTHER SIGNIFICANT MOONS IN OUR SOLAR SYSTEM THERE ARE OTHER MOONS IN OUR SOLAR SYSTEM THAT ARE OF GREAT INTEREST. THE PICTURE BELOW IS OF EUROPA, ONE OF JUPITER’S MOONS. IT IS INTERESTING BECAUSE IT IS COVERED IN WATER ICE.
THIS IS A CUTAWAY VIEW OF EUROPA. IT HAS AN IRON CORE AND AN OUTER LAYER OF WATER ICE AND A LAYER OF LIQUID WATER UNDERNEATH.
JUPITER’S MOON IO ORBITS CLOSER TO JUPITER AND IS SUBJECTED TO STRONG TIDAL FORCES. THIS RESULTS IN HEATING OF THE INTERIOR AND VOLCANIC ACTIVITY.
THE PICTURE AT THE LEFT IS IO IN ECLIPSE AND SHOWS ELECTRICALLY CHARGED VOLCANIC VAPORS. IO ORBITS INSIDE JUPITER’S STRONG MAGNETIC FIELD.
SATURN’S MOON TITAN HAS A HYDROCARBON ATMOSPHERE 1.6 TIMES DENSER THAN EARTH’S ATMOSPHERE. IT HAS LAKES OF LIQUID HYDROCARBONS.
VIDEO OF HUYGENS PROBE LANDING ON TITAN. NASA TITAN TOUR