Astronomical Odds and Ends in July
July 2004 :
Note: This article may contain outdated information
This article was published in the July 2004 issue of The Skyscraper and likely contains some information that was pertinent only for that month. It is being provided here for historical reference only.
My group set up our telescopes down at Pt. Judith. Sunrise was extremely cloudy. After about 15 minutes we finally got a six- or seven-minute look at the sun with Venus in transit before clouds obscured the view once again. During that brief time period the clouds were thick enough to afford us a view without filters. Not the best thing to do, but we only briefly glimpsed the image. The large black disk of Venus was very apparent. Number 14 welder's glass and special solar eclipse glasses enhanced the view.
The clouds finally parted an hour later and we were able to watch the rest of the event through completion. Venus' black disk was darker and more round than any sunspot I had ever seen on the surface of our Sun. We anxiously awaited the moment just before 3rd contact, when we expected to see the "black drop" effect.
We were not disappointed. All of a sudden the blackness of space outside of the solar disk seemed to drip inwards towards the disk of Venus approaching the solar limb or edge. It was a great phenomenon to observe. Slowly but surely (four or five seconds to this observer) the effect vanished as Venus' image began to exit the solar disk. We watched right up to the very end until that little notch of the planet's disk, like a little bite had been taken out of the sun, disappeared off the Sun's edge until 2012.
It was a great thrill to witness an event that had not been seen for 122 years. If you want to see some great images of the transit, including some fine shots of the "black drop" effect, please visit our website at ( http://www.theskyscrapers.org/ ).
Almost any sky show after such a historical event like the transit of Venus can seem very trivial and anti-climatic. However, the month of July does have some interesting astronomical tidbits for which to watch.
Do you want to see Venus again? Well, after its recent rendezvous with the sun, in July Venus will become a very prominent object in the early morning sky. Have you heard the phrase "once in a blue moon?" It refers to something that happens only once in a while. This year July is special because it has two full moons in it, one on July 2 and the second on the 31st. The second one is referred to as a blue moon.
Also in July the Earth is at its farthest point from the sun on the 5th, at 94,299,086 miles. In addition, another milestone will be celebrated on July 20th. Do you know what it is? On that date in 1969, Neil Armstrong first set foot upon the Moon. Buzz Aldrin soon followed him out onto the lunar surface. Ten more astronauts left their footprints on the Moon. Can you name them? All I can say is, you know you're getting old when you talk to young children when they view the moon through our telescopes at Seagrave Observatory and they tell you they learned about the Apollo moon landings in history class!!!!
The only other highlight for July is a couple of meteor showers at month's end. The first one, the Delta Aquarids, peak on the evening of the 27th to the early morning of the 28th. The Moon will be in a waxing Gibbous phase, a couple of days past first quarter. It will definitely interfere somewhat with observing all but the brightest of the meteors. Usually about 20 bright, yellow meteors can be observed per hour at peak. Because these meteors nearly broadside the Earth, their speed is a moderate 25.5 miles per second.
The second meteor shower, the Capricornids, come a day later on the night of July 29/30. The Moon will be even brighter, so I wouldn't expect very many to be seen. The Capricornids are characterized by their often yellow coloration and their frequent brightness. They are also slow interplanetary interlopers, hitting our atmosphere at around 15 miles per second. Expect perhaps less than eight meteors per hour at best, though the Capricornids are noted for producing brilliant fireballs.
Enjoy the astronomical tidbits the heavens provide for us during July. And just remember, it's never to late to plan ahead. See you in Hawaii on June 5/6, 2012 for the second of the current pair of Venus transits!!
Keep your eyes to the skies!
