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[...] to do it. Will us Earth-based amateurs one day watch the brilliant explosions visually�similar�to Iridium flares of Orion spacecraft departing on brave new voyages? One can only [...]
The Sky is Waiting.
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Pictured is a Delta IV rocket launch from Cape Canaveral on November 21st, 2010. The image is a 20 second exposure taken at dusk, shot from about 100 miles west of the launch site. The launch placed a classified payload in orbit for the United States Air Force.
Difficult but not impossible to catch against the dawn or dusk sky, spotting an extreme crescent moon can be a challenge. The slender crescent pictured was shot 30 minutes before sunrise when the Moon was less than 20 hours away from New.� A true feat of visual athletics to catch, a good pair of binoculars or a well aimed wide field telescopic view can help with the hunt.
The Sun is our nearest star, and goes through an 11-year cycle of activity. This image was taken via a properly filtered telescope, and shows the Sun as it appeared during its last maximum peak in 2003. This was during solar cycle #23, a period during which the Sun hurled several large flares Earthward. The next solar cycle is due to peak around 2013-14.
Located in the belt of the constellation Orion, Messier 42, also known as the Orion Nebula is one of the finest deep sky objects in the northern hemisphere sky. Just visible as a faint smudge to the naked eye on a clear dark night, the Orion Nebula is a sure star party favorite, as it shows tendrils of gas contrasted with bright stars. M42 is a large stellar nursery, a star forming region about 1,000 light years distant.
Orbiting the planet in Low Earth Orbit (LEO) every 90 minutes, many people fail to realize that you can see the International Space Station (ISS) from most of the planet on a near-weekly basis. In fact, the ISS has been known to make up to four visible passes over the same location in one night. The image pictured is from the Fourth of July, 2011 and is a 20 second exposure of a bright ISS pass.
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Next to the Sun, the two brightest objects in the sky are the Moon and the planet Venus. In fact, when Venus is favorably placed next to the Moon, it might just be possible to spot the two in the daytime. Another intriguing effect known as earthshine or ashen light is also seen in the image on the night side of the Moon; this is caused by sunlight reflected back off of the Earth towards our only satellite.
A mosaic of three images taken during the total lunar eclipse of December 21st, 2010. The eclipse occurred the same day as the winter solstice. The curve and size of the Earth�s shadow is apparent in the image.
AstroEvent of the Week: Spotting Iridium Flares.
Looking up at the dawn or dusk skies, it�s not uncommon to see a satellite brighten, flare up, and the abruptly disappear from view. What you�ve just seen is an Iridium flare, a glint of sunlight off of a refrigerator sized satellite�panel. Motorola launched this series of 66 communications satellites in 1997 through 1998 and they are currently owned and operated by Iridium Communications, Inc.
Their primary purpose is to provide worldwide coverage for satellite phones and data services, although the proliferation of cheaper cell tower technology worldwide assured that the sat phone concept never quite took off as envisioned. Catching an Iridium flare is quite a sight, as they can approach magnitude -8, or about 40 times brighter than Venus. Such luminosity can cast a shadow and easily be visible in the daylight. I�ve seen Iridium flares by chance before (they�re that prevalent!) but the best way to catch and photograph one successfully is to plan ahead. As we approach the autumnal equinox, the sun angle is such that Iridium flares in the dawn or dusk skies will be common worldwide. Regardless of your location, several flares may occur overhead on a daily basis. By far, the most reliable sight to track flares is Heavens Above. Simply load in your locale and it�ll give you local predictions for the next 48 hours, complete with a ground tracking map. The closer you can get to the track, the brighter the flare. Do watch a few minutes on either side of the prediction, as satellite orbits do evolve over time. Want to photograph a satellite flare? Simply tripod mount your camera, aim it in the direction the flare is supposed to occur, lock the shutter open (it has to be of the SLR variety, with a Bulb setting) and wait for the flare to occur. A few pretest shots to gauge sky brightness is handy, as twilight can change limiting exposure times dramatically�remember, digital film is cheap!
The Astroword for this week is: Satellite flare. These brilliant flashes are a result of a solar or communications panel catching the Sun high overhead at just the right angle. The Iridium constellation of satellites are the most famous for this phenomenon, but spy satellites such as the X-37B and even the International Space Station are known to flare occasionally. Discarded boosters are known to flash rhythmically as well; this is a result of tumbling motion prior to reentry. If you are diligent, all kinds of strange and wonderful sights will grace a local sky near you!