Moonlight Sonata

Moonlight Sonata

The man in the moon is actually a series of frozen lava fields. The moon is Earth’s only natural satellite and was probably created in the same cosmic event that created the Earth.

It is only 238,860 miles away, making it an object of endless human fascination – and superstition – for millennia. Although its only light is reflected from the sun, it is the brightest object in our night-time sky. In size it is slightly more than a quarter the diameter of the Earth.

Temperatures can be as high as 273 degrees Fahrenheit on the bright side and as low as -274 degrees Fahrenheit on the dark side. There is no air, and thus no liquid water, on the lunar surface. That means the moon has no clouds, winds, rain or snow. Without air and water to cause erosion, the moon’s features are nearly permanent – they include towering mountain ranges and seas of hardened lava.

The astronomer Galileo was the first to study many of these features with the telescope he built in the early 1600s.

The moon’s laval fields are called maria, after the Latin word mare for sea, because in Galileo’s time it was thought that these plains might in fact be oceans, and that there might be life on the moon. The maria look dark from Earth, suggesting to those with a vivid imagination that there is a “a man in the moon”.

The lunar surface has also been pitted with craters from crashing meteorites – over 30,000 can be seen from Earth. The circular depressions range in size from less than a mile to over 100 miles across.

As intriguing as all of these features are, however, none of them can compare with the fact that the pull of the moon’s gravity on the earth’s oceans plays a huge role in creating our daily tides.

The Phases of the Moon

The moon takes slightly longer than 27 days to complete its elliptical orbit around the earth, but because the earth also moves around the sun, it takes 29 days, 12 hours, 44 minutes and 3 seconds to go from one new moon to the next. At the start of each orbit, the moon is directly between the earth and the sun, making the moon invisible because its dark side is toward us.

Gradually, a crescent appears and the moon passes through a waxing phase, in which it grows progressively more visible until it becomes full, and then a waning phase, in which its shape gradually shrinks to invisible again before repeating the cycle.

The Moon has no light of its own : it merely reflects the light of the sun. If the moon did not rotate as it revolves around the earth, we would see all its sides; as it is, we always see the same side. Illustration: Moving beyond the Big Dipper.

If you are curious about what beside the North Star and the Big and Little Dippers are visible in the firmament tonight, don’t rush off to the book-store just yet; sorting through the hundreds of star-gazing guides that fill the racks could leave you more confused than you were to to begin.