JULY  2010

JULY STAR MAP | STARWATCH INDEX | MOON PHASE CALENDAR

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724    JULY 4, 2010:   Seeing Satellites from your Backyard

Summer is a great time to view the International Space Station or other satellites because the northern hemisphere is tilted towards the sun. This causes the sun’s angular distance below the horizon to be at a minimum, allowing its light to catch satellites well into the night. In order to see the ISS, or for that matter, flares from Iridium satellite solar panels, or the Hubble Space Telescope, you’ll need to be able to predict these events from the town or city in which you live. Enter heavens-above.com where these calculations can be made easily from literally any place on the globe. To log in, you can left click “from database” in the “Configuration” section at the top of the page. This will take you to a page where you can select a country. Click on the “U” in the alphabet listing; then click on “United States” when dropped down to that part of the page. In the “Search String” box, type the town in which you live. If your town is not unique, a listing of all towns in the US with that name will appear. Click on the appropriate one, and you will be taken back to the home page; but this time you will see your town listed right below “Configuration” as the “Current Observing Site.” Keep in mind that your position on the Earth will affect what you see in the sky, especially for the glints coming from Iridum satellites. If you live in a large metropolitan area or far from any designated town, your precise location can be entered “manually” as a latitude or longitude position or through the use of a Google map. With Google, I can select the front yard of my property, to get a precise printout if I care to be that particular. Keep in mind that the time of these events, especially for Iridium flares, are extremely precise, so you should purchase an atomic clock, one that receives updated signals from the National Institute of Standards and Technology or log onto www.time.gov/ for precision time.

725    JULY 11, 2010:   Moon, Planets, Stars Reveal Ecliptic

The ecliptic represents the plane of the solar system created by the Earth’s orbital motion around the sun. As Earth changes its location in its yearly circuit around our daystar, Sol reflects this change by shifting its position among the stars, giving us a seasonal change in the constellations that we view. The planets all lie near this plane, making them an excellent resource for viewing the ecliptic’s location during the night. Occasionally, bright stars situated near the ecliptic and the planets team up to make the ecliptic more vivid. This week, in addition to Mercury, Venus, Mars, and Saturn, the stars, Regulus and Spica, add to this line of pearls outlining the ecliptic against the western sky about 40 minutes after sundown. The waxing crescent moon plays below these objects during the course of the week. On July 11 the new moon eclipses the sun in the eastern Pacific crossing over Easter Island near day’s end. The following evening, the moon is below Mercury, but too close to the sun to be seen. July 13, about 40 minutes after sundown, finds the moon centered between Venus and Mercury. July 14 sees Venus, Regulus, and the moon in close association in the west an hour after sundown. By that time Mercury will have already set. On Thursday, the moon forms a more open grouping with Mars (above right) and Saturn (above left). Keep in mind that both planets have faded greatly since becoming visible this past winter, but they are still brighter than any of the stars of the Big Dipper. By Friday evening Luna is pulling away from Saturn, heading towards a Saturday rendezvous with the blue white gem, Spica, the alpha star of Virgo. The pair will fit nicely in the field of view of standard binoculars which should be brought along for the entire week if you’re planning to follow this mid-July parade. For the East Coast, the moon sets on Saturday evening just six hours shy of its first quarter phase.

726    JULY 18, 2010:   Dragon on View, Now!

High in the north above Polaris, right after darkness falls, is the star pattern of Draco the Dragon. It was my mystery constellation to thousands of groups of children and adults who visited my planetarium. “No pressure,” I’d say as my arrow swept over the curvaceous tail, the small, boxy body, the long spindly neck, and the distinctive quadrilateral head. I’d challenge, “No group from preschoolers to the elderly have ever missed it,” trying to elicit a response from my listeners. Then the answers would begin. “Is it a camel?” “Is it a lizard?” “Is it the scorpion?” “Is it a turtle”? “Is it a dragon?” Actually, all of the answers were appropriate, but the Dragon consistently elicited the greatest excitement. While eastern dragons were judged good, wise, and even worshiped, western dragons were considered evil. Draco fit neither grouping, and could best be described as gullible. As a guard dragon, Draco allowed his friend Atlas to steal the golden apples of the Hesperides which were Hera’s wedding gift to Zeus. The plan was hatched by Hercules as a solution to one of his 12 labors—his Get Out of Jail Free card—for having murdered his wife and children under Hera’s spell. In the tail of Draco is the star Thuban, famous for having been our North Star during the time that the Egyptian pyramids were built. It can be found perfectly centered between the three handle stars of the Big Dipper to Thuban’s left, high in the NW, and the two brightest cup stars of the Little Dipper to Thuban’s right in the North. Caesar’s fateful words, “I am as constant as the northern star,” in Shakespeare’s, Julius Caesar, applies only for limited time periods. Earth’s axis wobbles once every 26,000 years giving us a continuous parade of new North Stars. The blue-white star Vega, now overhead around midnight, will be our North Star by 14,000 AD.

727    JULY 25, 2010:   Planets Steal the Action

In the west the beautiful conjunction of Venus, Mars, and Saturn is rapidly unfolding. Monday’s full moon, rising at sunset, presents an opportunity of seeing the hazy, mellow hues of a summer twilight fade and blend into the long shadowed bluish whites of a bright moonrise. In order to catch the light show with all of its continuously morphing colors, observers will need a good western horizon to view the planets as well as a good southeastern vista so that the moon’s illumination can wash across the landscape against which the conjunction is taking place. Binoculars will make it obvious that Mars is gaining on Saturn. On Sunday, Mars will be one third degree from the star Beta Virginis, also known as Zavijava. The following evening that angular distance has increased to nearly one degree, 1.5 degrees by Tuesday, and over two degrees by Wednesday. At week’s end the Red Planet has caught up to and passed Saturn, looking as if it has left Venus in its dust. Fast forward two weeks, however, and the tables get turned on Mars as Venus seems to make its move and passes the God of War by mid-August. Venus will then nosedive towards the horizon as the planet comes about ready to pass between the Earth and the sun on October 29, leaving faint Mars the only survivor in the afterglow of sunset. Mars too will become lost in twilight in the SW after sundown by the end of October. Although this week’s dance of the planets in the west will be fun to watch, don’t forget about brilliant Jupiter debuting earlier and earlier each evening in the east. Jupiter is now rising just before 11 p.m., but give it some time to gain altitude. By 1 a.m. mighty Jove is just a little over two stacked fists held at arm’s length above the ESE horizon. If you are a night owl, this week will afford observers the opportunity of witnessing the moon catch up to and pass this giant world by Saturday morning.

Venus, Mars, and Saturn (right to left) join in saying hello on the evening of July 26. A 15 second guided image was taken at 9:47 p.m. EDT with a Canon 40D camera and 24-70mm zoom lens at an EFL of 56mm, F/4.0. A second image with the drive stopped was then snapped to capture the moonlit foreground. The two frames were combined into a single image using Paint Shop Pro. Gary A. Becker photography near Coopersburg, PA, Schantzenbach field...

Venus (right and brightest), Saturn (above) and Mars (below Saturn) played a game of hide and seek as clouds moved into the scene from the NE. Even Spica got into the act (upper left). Here they cooperated for the last time in this 15 second exposure, F/4.0, ASA 400, 56mm EFL image. Don’t think those rosy clouds are part of a summer’s sunset. That’s Allentown, PA spilling its sodium light into my Coopersburg sky. Still the effect was not objectionable. Gary A. Becker photography, Schantzenbach field...