Starwatch: Flying harp makes beautiful music in the summer skies
We have a new crescent moon showing up in the western Rochester sky later this week, which is always a celestial treat all by itself, but this Friday night, it will be extra special, as it will be parked just below and to the left of the extremely bright Venus.
Both celestial bodies will pop out during evening twilight in the low western sky. Pray for clear skies, because this should be a wonderful sight. If it's cloudy Friday night, it will be just about as good on Saturday night. The crescent moon will be a little fatter and it will be a little farther straight to the left of Venus.
Also look for a phenomenon called earthshine on the moon. Because of sunlight reflecting off the Earth, you may see not only the crescent moon bathed in direct sunlight but you could also see the rest of the moon's disk bathed in a light gray light. That's second-hand sunshine bouncing off the Earth to the moon. It's a real photo opp!
Another great thing about the crescent moon this week is that with the absence of heavy moonlight, the skies are a lot darker and the summer constellations really start leaping out at you. The constellation Lyra the Harp leads the way. The best way to find Lyra is to find its brightest star, Vega. The best way to find Vega is to find the Summer Triangle.
When it's finally dark enough on these mid-summer evenings, around 9:30 p.m. to 10 p.m., look for the three brightest stars you can find in the eastern half of the heavens. They will be arranged in a giant triangle. That's it, the Summer Triangle. You should have no doubt in your mind as to whether you picked the right three stars because they have no close rivals for brightness in that part of the sky. All three stars are the brightest stars in their own respective constellations.
The star on the lower left is Deneb, the brightest star in the constellation Cygnus the Swan. Deneb is at the tail of the southward flying swan.
The star on the lower right is Altair, marking the heart of Aquila the Eagle.
The highest and brightest star of the Summer Triangle is Vega. Not only is Vega the brightest shiner in the summer trio, it is the third-brightest star available in our night sky throughout the entire year. Vega was made famous in the movie "Contact," with Jodie Foster in the late 1990s, when her character and colleagues made electronic contact with an alien civilization on a planet orbiting Vega.
In the real universe, Vega is a star about 2 million miles in diameter, more than twice the diameter of the Sun. Vega is a much warmer star than our sun, however, with a surface temperature of nearly 17,000 degrees.
The reason Vega is so bright in our sky is twofold. First, it kicks out more than 40 times the light our sun does. Second, it's a relatively close star. Vega is 25 light-years away. That works out to about 145 trillion miles, which, believe it or not, is considered to be a nearby star! The light we see from Vega this summer left that bright star around the time George H.W. Bush was elected president in 1988.
Scientifically, the most interesting thing about Vega is that, in the last part of this past century, both ground- and space-based telescopes discovered that Vega has a distinct dust disk surrounding it. That may be a sign of a developing solar system, and in fact there may already be planets circling Vega. Stay tuned, because astronomers have already detected hundreds of planets orbiting other stars, and new discoveries are coming fast and furious.
Vega is also the brightest star in the small constellation Lyra the Lyre, which is an ancient version of a harp. About all there is to Lyra is Vega and four dimmer stars that hang below Vega in the shape of a small parallelogram. With your imagination in overdrive, you may be able to visualize it as a harp, but if you think you hear music, it may be time to head inside for some shut-eye!
According to Greek mythology, the constellation signifies the harp owned by Orpheus, the great musician who played his harp so well that he was able to charm the heck out of any person, animal, or monster. He used his harp as a wonderful tool to attract Eurydice, the love of his life. She instantly fell for Orpheus and his melodious tones and they were eventually married.
Tragically, Eurydice died at a young age and Orpheus fell apart at the seams. Pluto, the god of the underworld, felt so sorry for him that he made a deal to pull Eurydice out of the realm of the dead under one condition. Pluto demanded that Orpheus could not watch his wife actually being pulled out of Hades. As easy as that requirement sounds, Orpheus just couldn't resist gazing downward at his wife being towed out of the nether regions. He blew it! As soon as his eyes made contact with her, Eurydice was banished forever from his sight. Orpheus died a very broken man. Not even his own harp-playing could bring him out of his funk.
When he died, the rest of the gods of Mount Olympus took pity and placed his magical harp among the stars to make never-ending heavenly music.
The Perseids are arriving! One of the best meteor showers of the year is beginning this week. The peak of the Perseids is late next weekend and into the following week, but even now you can see some Perseid meteors or "shooting stars" racing across the sky.
The best time for viewing is in the hours after midnight leading up to the start of morning twilight. Lie back on the ground or in a reclining lawn chair and roll your eyes all around the sky to catch them. I'll have much more on the Perseid meteors next week in Starwatch.
Mike Lynch is an amateur astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis/St. Paul and is author of the book, "Stars, a Month by Month Tour of the Constellations" published by Adventure Publications. The Rochester Astronomy Club welcomes new members and puts on public star parties. Their website is www.rochesterskies.org