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[...] This post was mentioned on Twitter by David Dickinson. David Dickinson said: http://bit.ly/djnq7n Astro-Challenge of the Week: Aristarchus and the TLP. A small crater with a big mystery. [...]
The Sky is Waiting.
[...] This post was mentioned on Twitter by David Dickinson. David Dickinson said: http://bit.ly/djnq7n Astro-Challenge of the Week: Aristarchus and the TLP. A small crater with a big mystery. [...]
The Current Number of Exoplanets Discovered is: 4144
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.
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Astro-Challenge of the Week: Aristarchus & the TLP.
This week, we turn your attention to the waxing crescent Moon and an enduring mystery that surrounds a unique crater; Aristarchus. About 40 km across, this crater was named after the Greek scientist Aristarchus of Samos by map maker Giovanni Riccioli. This lone crater sits on the Aristarchus plateau amid the Mare Oceanus Procellarum. This crater is near the lunar limb and becomes visible during the early waxing crescent phase, and is markedly brighter than the surrounding lunar plains.
In fact, Aristarchus has an albedo of roughly twice that of ordinary craters, and may be noticeable to a sharply trained eye! The Soviet lunar lander Luna 13 stands as the closest successful landing to the crater, at 275 miles distant. And the mystery you may ask? Well, that’s our astro-term of the week: Transient Lunar Phenomena. Over the centuries of men staring at the Moon, anomalous reports of lights, flashes and curious brightenings have dotted observer’s journals. Aristarchus stands as the most frequent setting for TLPs over the years. These were variously attributed to fires, volcanoes, vegetation, and even intelligence on the Moon; none other than William Herschel believed that our nearest neighbor was inhabited by a race of “Moonmen,” and almost right up to the Apollo era, no one was truly certain that at least vegetation was absent on the lunar surface. TLP’s also make an appearance in Samuel Coleridge’s Rime of the Ancient Mariner, which also became the subject of what was termed the Coleridge Effect in Richard Baum’s The Haunted Observatory. An outstanding classic read on this and other astronomical oddities is A Catalog of Astronomical Anomalies by William Corliss. Of course, no moon-men or exotic lunar flora greeted Apollo astronauts; most TLPs have been attributed to observer error or optical illusions. A nagging handful may have been the occasional meteorite impact, or in the case of Aristarchus, an optical illusion coupled with the changing and oblique light angle of a crater near the lunar limb…still, it’s interesting to wonder just what those astronomers of yore might have seen. In 1911, an area just north of the crater on the Aristarchus plateau was analyzed by Robert Wood in the ultraviolet and found to contain a high concentration of sulfur. This patch is occasionally referred to as “Wood’s spot”. Even more interestingly, Apollo 15 made a direct pass over the Aristarchus plateau in 1971 and detected a high level of alpha particle emissions, highly suggestive of Radon-222 out-gassing. This was later confirmed by Lunar Prospector. Radon-222 only has a half-life of 3.8 days. Could Aristarchus be geologically active? As the Moon waxes towards first quarter, do give Aristarchus and its surrounding environs a close look!