You are here: Home / Archives for sheperd moons
The Sky is Waiting.
Search AstroGuyz
Custom Search
Advertise on Astroguyz!
|
|
|
 |
|
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.
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.
22.04.10-The Exotic World of Prometheus.
The moons of Saturn continue to astound. The count now stands at 61, and one by one, NASA’s Cassini orbiter is giving us a close up look at these unique worlds, some for the first time. Last year, Cassini passed within 36,000 miles of Prometheus just the day after Christmas. Discovered by Voyager 1 in 1980, this shepherd moon dips within the F-ring once every 15 hour orbit. This fact is apparent as the oblong cratered surface on the 74 mile long moon is coated with a fine layer of dust, giving it a smooth appearance. The constant “plowing” of these moons through Saturn’s rings cause the grooves that we see, and also confines the F-ring. These images are especially satisfying to Carolyn Porco, lead scientist of the Cassini research team who was also on hand for the tiny moon’s initial discovery by Voyager in 1980. It’s likely that we won’t get another look at this bizarre shepherd moon for some years to come!