Interesting Facts and Figures about the Moon

Interesting Facts and Figures about the Moon and its relationship to Earth:

DESCRIPTION OF LUNAR GEOGRAPHY

There is no Dark Side of the Moon. There is a Near Side (the side we see from Earth) and a Far Side (the side which always points away from Earth). Each side of the Moon receives periods of sunlight and darkness as it orbits around Earth.

Maria: The dark shades you see when you look at the Moon were named Maria by early astronomers. Maria, or Mare in singular form, means Seas in Latin. Early astronomers believed these dark areas were filled with water and hence the name. The Moon was once volcanic, much the way early Earth was, and these dark areas are the result of ancient lava flows. It is interesting to note that the majority of Mare is on on the near side, with only few areas on the Far side

Terrae: The lighter colored areas of the Moon’s surface are called Tarrae, which means highlands in Latin. The majority of the Moon’s surface is comprised of this type of geography. As an interesting note, the lowest area of the Moon is located on the Far side in an area called the South Pole Aitken Basin.

DEPICTION OF LUNAR MARIA ON THE NEAR SIDE MOON

CLICK ON THE LINKS LISTED BELOW FOR MORE INFORMATION ON THESE TOPICS:
http://en.wikipedia.org/wiki/List_of_maria_on_the_Moon
http://www.christa.org/moon.htm

GENERAL INFORMATION ABOUT EARTH'S MOON

Distance from Earth: The Moon’s distance from Earth varies because its orbit is elliptical rather than circular. At Apogee (when the Moon is farthest from the Earth), the distance is approximately 406,740 Km (approximately 252,736 statute miles) from Earth. When the Moon is at perigee (the closest point in its orbit to Earth) it is approximately 356,410 Km (approximately 221,462 statute miles) from Earth.

Size: The Moon has a diameter of approximately 3,474 Km (2,159 Statute Miles) and is about 1/4th the size of Earth, which has an approximate diameter of 12,742 Km (7,917 Statute Miles). To put the size of the Earth and Moon into perspective, the Sun has a Diameter of 1,380,000 Km (857,492 Statute Miles), which makes the Sun about 110 times the size of Earth. The Earth and Moon could fit inside the area of the Sun, with the same separation, or distances between them, and the Moon’s orbit would remain within the Sun’s diameter, with plenty of space left over. The Moon’s gravity is about 1/6th that of the Earth’s gravity.

Lunar Surface Temperatures: An average minimum lunar surface temperature is about -233°C (-387°F, during darkness at the poles) and an average maximum lunar surface temperature is about 123°C (253°F, during sunlight near the equator). It really depends upon where you are standing on the lunar surface (at the equator or the poles), and whether it is light or dark when you take the temperature reading.
The Apollo Moon landings occurred during the Moon’s First Quarter. The Apollo Landing sites were selected at a time near the Day/Night delineation line, when the Sun was low on the lunar horizon, in an attempt better regulate the lunar surface temperatures in a more suitable range for the Astronauts and their equipment.

Orbit: The Moon completes one orbit around the Earth, referred to as a Sidereal Month, every 27 Days, 7 hours, 43 minutes (approximately 27.3 days). As the moon orbits the Earth, it rotates on its axis (just as the Earth does on its axis). The reason we see the same side, or Face of the Moon, is that the Moons axial rotation is synchronized to its orbital rotation around Earth. Another way to say this is the Moon completes one axial rotation per one orbit around Earth, thus always displaying the same side to Earth. This was not always the case, the Moon used to spin much faster, but because of the Earth’s gravitational forces, the Moon has slowed to its present speed of rotation. This synchronized orbiting of Moons to planets is not uncommon in our solar system. All of Jupiter’s and Saturn’s Moons display this same synchronization.

Try the links listed below for more information on this topic:
http://www.nasa.gov/worldbook/moon_worldbook.html

Lunation: A lunation is the cycle of phases in one Synodic Month, which starts and ends with a new Moon (approximately 29 days, 12 hours and 44 minutes, or 29.5 days).

Differences Between Lunar Months: As the Moon completes one orbit around the Earth, the Earth has moved in its orbit around the Sun by approximately 26°. Because of the Earth’s movement, the Moon is not in exactly the same spot relative to the Sun when it completes its lunar orbit. It takes approximately 2 more days for the Moon to travel back to the same position relative to the Sun. This is why the lunar phase cycle, Synodic Month, takes approximately 29.5 days to complete even though the lunar orbit, Sidereal Month, was completed in approximately 27.3 days. Early cultures used the Synodic Month (Lunar Phases) as a basis for their calendars in order to count Earth days.

CROSS SECTION OF THE MOON

PHASES OF THE MOON

The Moon is constantly changing the amount of sunlight reflected back to Earth as it orbits our planet. Because of changes in position due to the Moon’s orbit and rotation of the Earth, the Moon goes through what scientists have called “phases”. The phases can be broken down by; New Moon, Waxing Crescent, First Quarter Moon, Full Moon, Last Quarter Moon, Waning Crescent, and finally the New Moon again. From this point, the Lunation cycle described above starts over and the cycle of phases is repeated.

New Moon: When the Moon is between the Earth and the Sun, with the Near side (side facing the Earth) entirely in darkness, the Mon is said to be a “New Moon”. The Moon is nearly invisible at this point, except during a solar eclipse.

Waxing Crescent: The Waxing Crescent stage occurs right after the New Moon phase, days 2 through 6 of the Lunation Cycle, when sunlight causes the Moon to appear as a crescent shape, illuminating only a small sliver of the Moon. The Moon is considered to be Waxing right after the New Moon when the amount of light is increasing as the Moon progresses from New Moon to First Quarter Moon.

First Quarter Moon: On the 7th day of the Lunation Cycle, half of the Moon is illuminated, as the area of sunlight reflected from the Moon back to Earth continues to increase towards a Full Moon.

Full Moon: A full Moon occurs on the 15th day of the Lunation Cycle and appears very bright in the night sky. The entire face of the Moon visible towards Earth is now illuminated by the Sun.

Last Quarter Moon: On the 23rd day of the Lunation Cycle (following the Full Moon), only half of the Moon is illuminated again and the amount of sunlight reflected towards Earth is decreasing every night.

Waning Crescent: The Waning Crescent stage occurs between the 24th and 29th days of the Lunation Cycle, until the Moon is New again. In the Waning Crescent stage, the amount of sunlight reflected back towards Earth continues to decrease until the Moon appears invisible again.

Try the links listed below for more information on this topic:
http://lunar.arc.nasa.gov/science/phases.htm
http://tycho.usno.navy.mil/vphase.html

Length of a Lunar Day/Night: One complete lunar day lasts an entire Synodic Month, or about 29.5 days. This means that there is approximately 2 weeks of constant light followed by 2 weeks of constant darkness in one lunar day (one complete revolution of the Moon on its axis).

ABOUT LUNAR LIBRATIONS

The word Librate comes from the Latin word libra, which means “To balance, To sway”. The Moon oscillates, or sways, throughout its orbit around the Earth. There are four types of Lunar Libration; Longitude, Latitude, Diurnal, and Physical. All of these librations allow an earthbound observer to see a total of approximately 59° of the lunar surface during one lunation.

Librations in Longitude: Because the Moon’s orbit is elliptical, its speed varies slightly. The Moon’s orbit speeds up at perigee (closest point to Earth) and is slowest at apogee (farthest point in orbit from Earth). This decreasing and increasing in the Moons orbital speed allows us to see slightly more or less of the Moon’s surface in an East to West direction. Put another way, because the Moon travels faster in orbit on either side of perigee, with its axial rotation remaining at a constant rate, starting from its point of perigee, it will move more than half way around its orbit before completing half of its axial rotation. This Orbital phenomenon allows earthbound viewers to see a little more around one side of the Moon than the Face presented at perigee. During the other half of the Moons orbit, this phenomenon allows earthbound viewers to see a little more around the other side. These East to West Librations are called Librations in Longitude and allow us to see a little more than 7° 50’ of the Moons Far Side.

Diurnal Librations: Is the result of the Earth’s rotation and how an earthbound observer moves as a result of this rotation. When the Moon rises in the East, an earthbound observer sees a little more around the eastern side. To put it in simpler terms; you can see a sliver of the far side towards the eastern edge of the Moon. Conversely, when the Moon is setting in the Western sky, an earthbound observer can see a sliver of the far side towards the Western edge of the Moon. Diurnal librations allow an observer to see roughly 1° of the far side.

Physical Librations: The Moon is not perfectly round; it is actually flatter at the poles and slightly elongated towards the Earth on the near side. The Earth’s gravitational pull on the Moon’s non spherical shape causes the Moon to sway or wobble in its axis. These librations are referred to as Physical Librations and their effect is very small (less than .05°). Physical Librations are not detectable to the naked eye even when using a telescope, but can be measured using lasers and bouncing their light off of equipment left by both Apollo and Soviet lunar missions.

Try the links listed below for more information on this topic:
http://en.wikipedia.org/wiki/Moon

GRAPHICAL DEPICTION OF DIURNAL LIBRATIONS

HOW WAS THE MOON FORMED?

One early theory suggested that Earth’s moon formed at the same time as the Earth and Mars, out of the same spinning mass of matter. There are other theories that suggest the Moon was formed somewhere else in the solar systems and was captured by Earth, or that the Moon was “cast off” from Earth at some point in its early development.
The latest theory to gain acceptance with the scientific community is the “Giant Impactor Theory”, which suggests that Earth’s Moon was formed when a giant Mars sized meteor hit Earth early in the formation of our solar system, taking a sizeable amount of Earth’s mass with it into orbit and it eventually formed into the Moon as we know it today.

Try the links listed below for more information on this topic:
http://www.novacelestia.com/space_art_solar_system/earth.html#moon_earth...
http://news.nationalgeographic.com/news/2007/12/071219-moon-collision.ht...

THE EFFECT OF THE MOON ON OCEAN TIDES

As the Moon orbits the Earth, both bodies exhibit gravitational forces on each other. The Moon and Sun are always tugging on Earth and the Moon’s gravitation “tug” is carried with it as the Earth rotates about its axis. The Earth’s Oceans actually bulge out in the direction of the Moon. There are two high and low tides each day, with approximately 12 and a half hours between each high tide.

Spring tides occur during the Full and New Moon phases when the Moon and Sun are aligned in a pattern that allows the greatest gravitational tug on Earth. Spring tides are the strong, or large tides.

Neap tides occur when the sun and Moon are not aligned and the gravitational pull is at a minimum, causing only minimal tides.

Try the links listed below for more information on this topic:
http://home.hiwaay.net/~krcool/Astro/moon/moontides/
http://en.wikipedia.org/wiki/Tides

There are also theories that the Moon affects human behavior. These theories were developed centuries ago but modern scientific study does not support them.

Try the link listed below for more information on this topic:
http://en.wikipedia.org/wiki/Lunar_effect

LUNAR ECLIPSES

The Lunar Eclipse: Lunar Eclipses occur when the Moon passes through a portion of the Earth’s shadow. Lunar eclipses can only be seen during a full Moon. Lunar eclipses usually occur between 2 to 4 times per year. Some of the lunar eclipses are full eclipses (Total Eclipses) and some are only Partial Eclipses. There is another type of eclipse not visible to the naked eye called the Penumbral Lunar Eclipse.

SOLAR ECLIPSES

The Solar Eclipse: A Solar eclipse occurs when the Moon passes between the Earth and Sun causing either a Total or Partial Eclipse. Solar Eclipses only occur during the New Moon (Contrary to Lunar Eclipses which only occur during a Full Moon). Solar Eclipses are rarer than Lunar eclipses and Total Solar eclipses are very rare because the area on Earth you would have to be standing in to see the Total Solar eclipse is only about 62 miles wide.

Click on the links listed below for more information on eclipses:
http://sunearth.gsfc.nasa.gov/eclipse/lunar.html
http://www.mreclipse.com/Special/LEprimer.html
http://en.wikipedia.org/wiki/Lunar_eclipse
http://en.wikipedia.org/wiki/Solar_eclipse

What is my age in lunar years?

Have you ever wondered what is my age in lunar years? Did you know that the calendar we use today was not the first calendar created? Prior to our current Western solar calendar, many civilizations used purely Lunar calendars or a combination of Lunar and Solar calendars called Lunisolar. There is a link below to calculate what is my age in lunar years, but if you want more information on this subject, read on.

Most lunar calendars are lunisolar; the Chinese, Hebrew, and Hindu calendars are examples of cultures that have used lunisolar calendar systems, and for the answer to the question what is my age in lunar years, the link below will take you to a page that will estimate your age based on the Chinese Lunar Calendar. Other systems were purely lunar; such as the Islamic calendar or Hijri, whose year always consists of 12 lunar months and is based only on phases of the Moon meaning it does not keep in sync with the solar year or seasons.

A lunar month is approximately 29.5 days, which equals one lunar phase cycle or synodic month. A synodic month is the time it takes the moon to complete one orbit around the Earth and travel back to the same spot in the sky from where it begun. When asking what is my age in lunar years, one is usually referring to the Chinese Lunar calendar which was used as the primary calendar in China until 1912. The old system still serves as the basis for determining numerous seasonal holidays in China and other cultures. When entering your data to calculate what is my age in lunar years, you will find that you are actually older using the Chinese Lunar Calendar then the current western system. The reason is two fold. First, the synodic month is shorter than most months in the standard calendar and second, the Chinese begin calculating age starting at the point of conception, so when a child is born, they are almost a year old when they leave the mothers womb. So, if you are trying to retain your youth, don’t ask what is my age in lunar years, just be happy with the age you have now.

Click on the link below for a calculator that will help answer what is my age in lunar years
http://fortuneangel.com/CAge2.htm

Links to other Websites with good Lunar information:

http://www.astro.uu.nl/~strous/AA/en/antwoorden/maan.html
http://pirlwww.lpl.arizona.edu/~jscotti/apollo.html
http://www.physicstoday.org/vol-58/iss-2/p26b.html
http://www.space4peace.org/moon/moon.htm
http://search.nasa.gov/search/search?as_sitesearch=aerospacescholars.jsc...

Links to articles descirbing other Nation's plans for returning to the Moon:

http://thescotsman.scotsman.com/world/Chinas-moon-programme-achieves-liftoff.3473740.jp
http://thescotsman.scotsman.com/science/Nasa-counts-down-for-return.2662091.jp
http://www.nasa.gov/mission_pages/constellation/main/index.html
http://www.thespacereview.com/article/478/1
http://www.csmonitor.com/2007/1001/p01s06-ussc.html
http://www.msnbc.msn.com/id/7046936
http://www.spaceref.com/news/viewnews.html?id=1131
http://www.usatoday.com/tech/science/space/2005-09-19-moon-trip_x.htm
http://www.dailytech.com/Russia+Plans+Manned+Mission+to+Moon+by+2025/article8687.htm
http://www.ocregister.com/science-technology/space-satellites-earth-1854333-india-launch
http://www.news24.com/News24/Technology/News/0,,2-13-1443_1625814,00.html

Links to more Lunar and Apollo photos:

http://www.nasm.si.edu/collections/imagery/apollo/apollo.htm
http://www.lpi.usra.edu/
http://www.apolloarchive.com/apollo_gallery.html
http://moonpans.com/
http://astrogeology.usgs.gov/Projects/LunarAtlas/panoramas/
http://www.inconstantmoon.com/atlas.htm
http://www.panoramas.dk/moon/mission-apollo.html
http://www.oarval.org/MoonMapen.htm
http://images.google.com/imgres?imgurl=http://www.lpi.usra.edu/resources...
http://www.mariannedyson.com/moon.htm
http://www.lpi.usra.edu/resources/apollo/
http://www.stargazing.net/david/moon/day14h6moon.html