Looking Up: This week's moonless sky offers prime conditions for stargazing
Moonless evening skies prevail this week in the northern Poconos. This is prime time away from city lights to take in the rhapsody of the summer night sky.
On late July evenings, as darkness settles in after about 10 p.m. Scorpius the Scorpion adorns the southern sky, dominated by its red celestial heart, the bright red supergiant star Antares. The Scorpion's "pincers" are easily imagined connecting stars to the upper right of Antares. Tracing stars down to the lower left one can imagine the tail. Look for the two fairly bright stars here fairly close together. They are nicknamed the "Cat's Eyes."
From even a semi-rural location you will hopefully be able to trace the Milky Way Band arcing across the sky from the south, high up in the east at this hour and descending to the north-northeast. Immediately east (left) of the Scorpion is the familiar "Teapot" star pattern (asterism which is part of the constellation Sagittarius the Archer.
In this area of the sky the Milky Way is brightest and widest; it is best appreciated from a dark site in southern latitudes, especially the Tropics, where it is very high up in the sky. It is still beautiful here from mid-northern latitudes like here in Pennsylvania, on a good night and away from town lights.
Amazingly, the Milky Way seems to billow from the Teapot's "spout" as if it were steam. Of course, it doesn't show any movement. This bright part of the Milky Way is the hub of the Milky Way spiral galaxy which we see from within one of the spiral arms.
More Looking UpPocono stargazers may want to wait up for summer stars
The galaxy is a dusty place; the interstellar medium has huge amounts of molecular dust grains and gas. Just look up at the Milky Way Band on a dark July night and see the great split. In the area from the constellation Aquilia the Eagle through Cygnus the Swan, the Milk Way seems to divide. What is really occurring is that a great stretch of dusty, gaseous nebula is hiding the stars of the Milky Way Band in the background.
The brightest star of the summer night, bluish-white Vega shines nearly overhead as twilight ends in late July. To the right and also at or near the zenith (the overhead point) are the four stars of the "Keystone", an asterism that is part of the constellation Hercules. On the west side of this parallelogram, use binoculars to locate what appears like a very fuzzy star. This is M13, the great globular cluster of Hercules. From a very dark site you can glimpse it with the naked dye.
It is one of hundreds of globulars that travel with our galaxy and visible in even a small telescope. They are dense "cities" of stars. M13 is some 25,000 light years away, and has hundreds of thousands of stars in an area only 150 light years across. Near the core there are about 100 stars in a cubic area three light years on a side.
For comparison, the star system closest to the Sun, Alpha Centauri, is about four light years away. Imagine the night sky from inside M13!
Be sure to watch for planet Saturn; at 10 p.m. it's still very low in the east - southeast; by midnight it is well up in the southeast and Jupiter has joined the sky low in the east. Mars is low in the east before 2 a.m. The Moon is an early morning crescent, leading up to the New Moon on July 28.
Don't miss the stars of this show.
Keep looking up at the stars!
This article originally appeared on Tri-County Independent: Here's how you can view Milky Way, M13 cluster in northern Pocono sky
