The Moon is Earth's only natural satellite and formed approximately 4.5 billion years ago from debris left over from a giant impact between Earth and a Mars-sized body. It has various phases as it orbits Earth over approximately 29.5 days. Eclipses occur when the Moon passes into Earth's shadow or Earth passes into the Moon's shadow. There is renewed interest in colonizing the Moon due to indications that water may exist at the lunar poles.

2. THE MOON (GREEK: ΣΕΛΉΝΗ, SELENE; LATIN: LUNA) IS EARTH'S ONLY NATURAL SATELLITE. IT IS ONE
OF THE LARGEST NATURAL SATELLITES IN THE SOLAR SYSTEM, AND, AMONG PLANETARY SATELLITES,
THE LARGEST RELATIVE TO THE SIZE OF THE PLANET IT ORBITS (ITS PRIMARY). IT IS THE SECOND-
DENSEST SATELLITE AMONG THOSE WHOSE DENSITIES ARE KNOWN (AFTER JUPITER'S SATELLITE IO).
THE MOON IS THOUGHT TO HAVE FORMED APPROXIMATELY 4.5 BILLION YEARS AGO, NOT LONG
AFTER EARTH. THERE ARE SEVERAL HYPOTHESES FOR ITS ORIGIN; THE MOST WIDELY ACCEPTED
EXPLANATION IS THAT THE MOON FORMED FROM THE DEBRIS LEFT OVER AFTER A GIANT IMPACT
BETWEEN EARTH AND A MARS-SIZED BODY CALLED THEIA.

3. EACH MONTH OUR MOON PASSES THROUGH EIGHT PHASES. THESE PHASES ARE NAMED AFTER HOW
MUCH OF THE MOON WE CAN SEE, AND WHETHER THE AMOUNT VISIBLE IS INCREASING, OR DECREASING
EACH DAY.
IT TAKES OUR MOON ABOUT 29.5 DAYS TO COMPLETELY CYCLE THROUGH ALL EIGHT PHASES.
OCCASIONALLY (ABOUT EVERY 2.7 YEARS) THERE ARE TWO FULL MOONS IN THE SAME MONTH. THIS IS
REFERRED TO AS A BLUE MOON. HENCE THE SAYING "ONCE IN A BLUE MOON".

4. AN ECLIPSE IS AN ASTRONOMICAL EVENT THAT OCCURS WHEN AN ASTRONOMICAL OBJECT IS TEMPORARILY
OBSCURED, EITHER BY PASSING INTO THE SHADOW OF ANOTHER BODY OR BY HAVING ANOTHER BODY PASS
BETWEEN IT AND THE VIEWER. AN ECLIPSE IS A TYPE OF SYZYGY.
THE TERM ECLIPSE IS MOST OFTEN USED TO DESCRIBE EITHER A SOLAR ECLIPSE, WHEN THE MOON'S SHADOW
CROSSES THE EARTH'S SURFACE, OR A LUNAR ECLIPSE, WHEN THE MOON MOVES INTO THE EARTH'S SHADOW.
HOWEVER, IT CAN ALSO REFER TO SUCH EVENTS BEYOND THE EARTH–MOON SYSTEM: FOR EXAMPLE, A PLANET
MOVING INTO THE SHADOW CAST BY ONE OF ITS MOONS, A MOON PASSING INTO THE SHADOW CAST BY ITS HOST
PLANET, OR A MOON PASSING INTO THE SHADOW OF ANOTHER MOON. A BINARY STAR SYSTEM CAN ALSO
PRODUCE ECLIPSES IF THE PLANE OF THE ORBIT OF ITS CONSTITUENT STARS INTERSECTS THE OBSERVER'S POSITION.

5. A LUNAR ECLIPSE OCCURS WHEN THE MOON PASSES
DIRECTLY BEHIND THE EARTH INTO ITS UMBRA (SHADOW).
THIS CAN OCCUR ONLY WHEN THE SUN, EARTH AND MOON
ARE ALIGNED (IN "SYZYGY") EXACTLY, OR VERY CLOSELY
SO, WITH THE EARTH IN THE MIDDLE. HENCE, A LUNAR
ECLIPSE CAN OCCUR ONLY THE NIGHT OF A FULL MOON.
SOLAR ECLIPSE
AS SEEN FROM THE EARTH, A SOLAR ECLIPSE IS A TYPE OF
ECLIPSE THAT OCCURS WHEN THE MOON PASSES BETWEEN
THE SUN AND EARTH, AND THE MOON FULLY OR PARTIALLY
BLOCKS ("OCCULTS") THE SUN. THIS CAN HAPPEN ONLY AT
NEW MOON, WHEN THE SUN AND THE MOON ARE IN
CONJUNCTION AS SEEN FROM EARTH IN AN ALIGNMENT
REFERRED TO AS SYZYGY.

6. THE GIANT-IMPACT HYPOTHESIS, SOMETIMES CALLED THE BIG SPLASH, OR THE THEIA IMPACT SUGGESTS THAT EARTH'S
MOON FORMED OUT OF THE DEBRIS LEFT OVER FROM AN INDIRECT COLLISION BETWEEN EARTH AND AN
ASTRONOMICAL BODY THE SIZE OF MARS, APPROXIMATELY 4.5 BILLION YEARS AGO, IN THE HADEAN EON; ABOUT
20 TO 100 MILLION YEARS AFTER THE SOLAR SYSTEM COALESCED. THE COLLIDING BODY IS SOMETIMES CALLED
THEIA, FROM THE NAME OF THE MYTHICAL GREEK TITAN WHO WAS THE MOTHER OF SELENE, THE GODDESS OF THE
MOON.

7. THE COLONIZATION OF THE MOON IS THE PROPOSED ESTABLISHMENT OF PERMANENT HUMAN COMMUNITIES OR ROBOT
INDUSTRIES ON THE MOON.RECENT INDICATION THAT WATER MIGHT BE PRESENT IN NOTEWORTHY QUANTITIES AT THE
LUNAR POLES HAS RENEWED INTEREST IN THE MOON. POLAR COLONIES COULD ALSO AVOID THE PROBLEM OF LONG
LUNAR NIGHTS – ABOUT 354 HOURS, A LITTLE MORE THAN TWO WEEKS – AND TAKE ADVANTAGE OF THE SUN
CONTINUOUSLY, AT LEAST DURING THE LOCAL SUMMER (THERE IS NO DATA FOR THE WINTER YET).PERMANENT HUMAN
HABITATION ON A PLANETARY BODY OTHER THAN THE EARTH IS ONE OF SCIENCE FICTION'S MOST PREVALENT THEMES.
AS TECHNOLOGY HAS ADVANCED, AND CONCERNS ABOUT THE FUTURE OF HUMANITY ON EARTH HAVE INCREASED, THE
ARGUMENT THAT SPACE COLONIZATION IS AN ACHIEVABLE AND WORTHWHILE GOAL HAS GAINED MOMENTUM. BECAUSE
OF ITS PROXIMITY TO EARTH, THE MOON HAS BEEN SEEN AS THE MOST OBVIOUS NATURAL EXPANSION AFTER EARTH.
THERE ARE ALSO VARIOUS PROJECTS IN NEAR FUTURE BY SPACE TOURISM STARTUP COMPANIES FOR TOURISM ON THE
MOON.

8. HTTPS://WWW.YOUTUBE.COM/WATCH?V=SDTW-TWEQZG
MOON BASE
HTTPS://WWW.YOUTUBE.COM/WATCH?V=YV9HMW64E60