Win tickets to see the smash hit musical Mamma Mia at the Roanoke Civic Center. Two winners will each receive four tickets!
Saturday, June 29, 2013
"Why did not somebody teach me the constellations and make me at home in the starry heavens, which are always overhead, and which I don't half know to this day?"
- Thomas Carlyle
(1795-1881), English writer
Warm July evenings invite skywatchers to relax in the deepening twilight and watch celestial wonders emerge, one by one. Seize the chance that Thomas Carlyle missed.
Only thirty minutes after the sun sets, the first point of light to appear is Venus, steadily shining low in the west-northwest. Ten minutes later the first true star shows itself. Arcturus, the second brightest star as seen from Southwest Virginia, sparkles high in the south with a slightly yellowish tint. Shortly afterward, high in the east, the third brightest star, blue-white Vega, pops into view followed by the planet Saturn lying below Arcturus.
By 9:45 a hundred twinkling pinpoints are sprinkled across the still blackening sky. Among them are the stars of the sky's most famous grouping, the Big Dipper. Look nearly overhead and slightly to the northwest to spot its familiar seven lights.
An unfortunate boundary - one that has become too common in our area - is reached about 10 p.m. If you live in a city, light pollution denies you the chance to see the dimmer stars fill the sky. While you can spot the first one hundred stars, you miss the next thousand. If you live in a rural area, though, new stars keep coming into view until astronomical twilight ends about 10:45.
This begins the period to enjoy the full splendor of what the night sky offers. With all the stars sparkling above, you may feel overwhelmed at what you see. How on earth can you find your way around the heavens?
The key is to take your time in becoming familiar with small areas of the sky. One worthwhile section containing two interesting star patterns lies nearly overhead in early July evenings. First, though, positively identify Arcturus by extending the curve of the Big Dipper's handle until it strikes it. To its far upper left, the nearly equally bright Vega twinkles almost overhead.
Draw an imaginary line from Arcturus to Vega. One-third of the way between them sits the small but pretty constellation Corona Borealis, or Northern Crown, which resembles what its name implies. Indeed, a semi-circle of seven stars outlines a celestial crown flaunting a central jewel, a star appropriately named Gemma.
While enjoying the beauty, consider the mystery. All the spectacular photographs taken by today's large telescopes show objects that are located somewhere in the heavens.
West of Gemma resides a large cluster of galaxies far too faint to be seen with binoculars or even a small telescope. The Corona Borealis Galaxy Cluster, studied extensively by astronomers seeking to unravel the puzzle of galactic evolution, lies an incredible 2 billion light-years away. It is mind-boggling to think that the cluster's feeble light left those galaxies when only single-cell organisms lived in Earth's early oceans!
Next, travel another third of the imaginary line's length to a star pattern known as the "Keystone." City lights all but obliterate these four faint stars, but dark rural skies bring them into view. Taking the shape of a keystone, they form the body of the much larger constellation Hercules. Binocular users can spot a small, misty glow situated along the western edge of the Keystone. Telescopes reveal this to be an immense ball of stars - a globular cluster - with well over 200,000 members.
It appears to us as an insignificant patch of light simply because it sits 25,000 light-years away.
On the next dark night, spend time looking for the Northern Crown and the Keystone. Once you befriend them, these two distinctive star patterns will greet you warmly every summer night.
Weather JournalNext system: Possible ice/snow Sat.