CAYMAN ISLANDS ASTRONOMICAL SOCIETY
NEWSLETTER AUGUST 2007
We will aim to meet this month on Wednesday, 15th August, 7.30.p.m. at Pedro Castle, weather permitting.
The Perseid Meteor Shower occurs on August 12-13th. This year the new moon will leave the sky dark. Look to the eastern sky in the constellation Perseus. Between 2 a.m. and dawn on August 13, if you get away from city lights, you could see hundreds of meteors.
This is one of the best showers of the year. The Perseids are a result of debris in space left by comet Swift-Tuttle. Although the comet is nowhere near Earth, the comet's wide tail does intersect Earth's orbit. We glide through it every year in July and August. Tiny bits of comet dust hit Earth's atmosphere traveling 132,000 mph. At that speed, even a tiny smidgen of dust makes a vivid streak of light--a meteor--when it disintegrates. The shower is most intense when Earth is in the dustiest part of the tail.
The mythological illustration that I used last month included the constellation Scorpius, more schematically shown above.
Jupiter, the fourth brightest object to light up the heavens, after the sun, moon, and Venus, shines unmistakably in the southern part of the sky, and serves as a guide to the Scorpion.
This is a distinctive constellation with its wide head and body curving to its tail. Glowing with a reddish hue at the heart of this asterism is the bright star Antares, the sixteenth brightest in the sky, although out shone this month by close Jupiter.
Antares is in the middle of the scorpion's curving body and rivals Mars in its reddish tint. This brilliant red star is one of the behemoths of our stellar neighborhood. If you placed it at the center of our own solar system, it would swallow Mercury, Venus, Earth, and Mars, and almost reach Jupiter.
The Scorpion was sent by Gaia to kill Orion when Orion boasted he would slay all the animals of the Earth; now Orion and Scorpius circle each other on opposite sides of the sky.
The Chinese included these stars in the Azure Dragon, a powerful but benevolent creature whose rising heralded spring, and in Maori mythology, this constellation can be Maui's magic jawbone used to fish up the North Island of New Zealand.