Moon Minutae
Posted on: Friday, 9 July 2004, 06:00 CDT
* The moon is Earth's only natural satellite. It is 2,160 miles across, is an average of 238,900 miles from Earth and orbits our planet once every 27.32 days. It is estimated to be 4.76 billion years old.
* There is no "dark side of the moon." The moon has synchronous rotation; that is, it keeps the same side toward Earth at all times. Since this means the moon rotates once on its axis in the same time it completes one orbit, a lunar day is as long as a lunar year.
* The percentage of the moon we observe -- its phases -- is a result of the moon orbiting Earth and our view of the half illuminated by the sun changes.
* The origin of our modern month comes from our ancestors' observation of the roughly 30-day cycle of the moon around Earth.
* It is not the nature of terrestrial planets, like Earth, to have moons. The origin of our moon is still being studied, but evidence suggests that the moon was once a piece of Earth that broke off due to an impact with another body. This would explain the moon's orbit and its lack of a metal core, as well as Earth's rapid rotation.
* The moon and Earth may be considered a double planet.
* The moon is a moon, but does it have a name? Some sources will list the actual name of the moon as "Luna," hence the adjective "lunar." Other sources report the name as Diana, the classical goddess of the hunt.
* There are two different tides every month, caused by a gravitational tug-of-war between Earth and the sun that pulls on Earth's oceans. Neap tides occur when the moon is at its first or last quarter phase. Spring tides, which are much more dramatic, occur at new or full moon when the sun, Earth and moon are in a straight line.
* What we witness as tides is actually Earth rotating under the planetary tidal bulge, which doesn't change shape much in a day.
* The moon is actually getting farther away from us. As Earth rotates, it "drags" the tides with it due to friction, acting like a brake on the moon. As gravitational energy is lost, the moon slows down and its orbit gets larger.
* Biologists say that the moon played an important role in the evolutionary history of this planet: the ability to breath dry air and survive out of the water was motivated by the tides pushing and abandoning life on land.
Related Articles
- China's Lunar Orbiter Heads Toward Moon
- Europe Goes Searching for Earth-like Planets
- Earth-Like Planets May Be Common in Known Planetary Systems
- Space Shield Could Help Image Earth-Like Planets
- SMART-1 Uses New Imaging Technique in Lunar Orbit
- Surfing the Wavelengths in Search of Earth-like Planets
- Slow and Steady Wins Race for Europe's Lunar Orbiter
- China to Launch Lunar Orbiter
- Europe's Mission to Moon Nears Lunar Orbit
- Japanese Lunar Orbiter Faces New Delay
 |
 |
User Comments (0)
RSS Feeds