NIGHT SKIES OVER PLACENCIA
DECEMBER 2005
DEFINING THE SKIES

          When it comes to the skies overhead, find out just what you may, or may not, be seeing.
Sun: the huge star in the sky that provides heat and light, sustaining life on Earth; any star around which a planetary system evolves. Our Sun has a radius of 435,000 miles: considered a medium-sized star), mass of 330,000 Earth masses, and a surface temperature of 10,000 degrees Fahrenheit. It also has the capacity to turn tourists into Lobsters!
Star: a very large ball of burning gas in space which is usually seen from Earth as a point of light in the sky at night, radiating energy derived from thermonuclear reactions in the interior; Red Dwarf star: a small cool star; approximately 100 times the mass of Jupiter; Red Giant star: A star of great size and brightness that has a relatively low surface temperature.
Moon: the natural satellite of the Earth, whose average distance from us is 238,000 miles; also a small body in orbit about any planet. Blue Moon: The current popular definition is the second full moon in one month, however it is an actual phenomenon caused by dust or ash in the atmosphere at very high altitudes.
Planet: any of the nine large celestial bodies in our solar system that revolve around the sun and shine by reflected light; Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in order of their proximity to the sun. Viewed from the constellation Hercules, all the planets rotate around the sun in a counterclockwise direction. Brown dwarfs are failed stars. Though huge, they never grew massive enough to initiate the thermonuclear fusion that drives a real star.
Comet: Made of dust, ice, carbon dioxide, ammonia and methane, Comets orbit the Sun. As a comet nears the Sun, its icy core boils off, forming a cloud of dust and gas called a head, which is ‘blown away’ and illuminated as it nears the sun, causing it to appear to have a tail. A comet's tail always points away from the Sun. When Earth crosses the path of a comet, even if the comet hasn't been around for a few years, leftover dust and ice can create increased numbers of meteors.
Meteor: A meteor compresses air in front of it. The air heats up, in turn heating the meteor. Heat vaporizes most meteors, creating what we call shooting stars (most become visible at around 60 miles up) traveling around 30,000 miles per hour. Some large meteors splatter, causing a brighter flash called a fireball, and an explosion, which can often be heard up to 30 miles away. Why are the hours between midnight and dawn typically the best time to watch a meteor shower? The part of Earth where dawn is breaking is always at the leading edge of our planet's plunge along its path around the Sun. This part of the planet tends to "catch" oncoming meteors left by a comet,
Meteorite: When meteors hit the ground, they're called meteorites. Some meteors are bits broken off asteroids, others -- mere cosmic dust -- are cast off by comets. (And one more term: A meteoroid is an object in space that may, IF it enters our atmosphere, become a meteor.) Extraterrestrial objects that hit the ground, their speed roughly half what it was upon entry, blast out craters 12 to 20 times their size.
Asteroid: Minor planets. Most, but not all, orbit the sun in an asteroid belt between Mars and Jupiter. The lightest-looking asteroids are rocky bodies with lots of iron and nickel, and they resemble lunar rocks. The darkest asteroids have high quantities of hydrated minerals and carbon. When an asteroid, or a part of it, crashes into Earth, it's called a meteorite. They are actually bits and pieces of space objects that never quite joined together to form a planet.
Galaxy: A system of about 100 billion stars bound by gravity. Our Sun is a member of the Milky Way Galaxy, which is sometimes just designated by capitalization: Galaxy. There are billions of galaxies in the universe. Our own galaxy, the rim of which we see as the “Milky Way,” is about 100,000 light-years in diameter and about 10,000 light-years in thickness.
Universe: The universe is everything, all matter and energy that is in existence.
Constellation: a configuration of stars as seen from Earth, that make a shape (they look like connect-the-dots) - usually named after mythological characters, people, animals and things.
Zodiac: The twelve constellations through which the elliptic - the apparent path in the sky followed by the sun, moon and most planet - passes. They are: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, and Pisces.
Moon Phases: Distinct, traditionally recognized stages of the moon, whose complete phase cycle is 29.5 days: new moon, waxing crescent (the beginning of a month in the Islamic Calendar), first quarter, waxing gibbous, full moon, waning gibbous, last quarter, waning crescent.
Speaking of the Moon: New Moon: 1 December, First Quarter: 7 December, Full Moon: 15 December, Last Quarter: 23 December, New Moon (again!): 30 December. Best Days for fishing this month, according to the Moon: ***: 7th and 8th; **: none; *: 9th, 16th, 17th, 26th, 27th. Happy New Year!

A beautiful composite of phases of our Moon.