On a rare foggy night, mysterious laser beams seem to play across the MAGIC telescope at Roque de los Muchachos on the Canary Island of La Palma. The lasers are actually part of a system designed to automatically adjust the focusing of the innovative, seventeen meter wide, multi-mirrored instrument. The MAGIC (Major Atmospheric Gamma Imaging Cherenkov) telescope itself is intended to detect gamma rays - photons with over 100 billion times the energy of visible light. As the gamma rays impact the upper atmosphere they produce air showers of high-energy particles. The MAGIC camera records in detail the brief flashes of optical light, called Cherenkov light, created by the air shower particles that ultimately correspond to cosmic sources of extreme gamma-rays. While the MAGIC I telescope became operational this year, the dramatic picture shows the nearly completed version of the instrument in October 2003.
Picture taken during the preparations for the inauguration of the MAGIC telescope in October 2003. The picture has been included in the recently published book "Astronomy365 days" by Jerry Bonnell & Robert Nemiroff. (There is also a German version of this book available"Das Weltall. Tag für Tag").
The photo above shows an eyecatching circumhorizontal arc and was captured near Lindau, Germany on June 30, 2004. The Sun, though not visible, is positioned above this arc. Circumhorizontal arcs and the more frequently observed circumzenithal arcs are complementary halos.
Picture taken during the 54th Meeting of Nobel Laureates in Lindau, Germany on June 30, 2004.
This picture showing a caustic network was taken in a natural salt water swimming pool near La Fajana, on La Palma (Canary Islands), Spain. An undulating surface of water acts like an arrangement of concave and convex lenses, causing an uneven brightness distribution at the bottom of a pool or even a shallow sea floor. The brighter blotches are in crude focus. The dispersion of water (the refractive index is different for different colors) is partially responsible for the observed color patternsthe height of the waves determines the focal length of the formed "lenses." This effect also causes the sometimes observed shadow bands during solar eclipses and is best seen when the water's depth is about 5 times the waves crest to crest distance.
Picture taken on January 25, 2002.
The above photo shows the fascinating limestone terraces at Pamukkale, in southwestern Turkey --"Pamukkale" means cotton castle in Turkish. They're approximately 2,700 m (8,800 ft) long and 160 m (525 ft) high. Though they resemble frozen waterfalls, these terraces are composed of calcite and aragonite, which are crystalline forms of calcium carbonate (travertine). Photo taken on March 30, 2006.
(Photo taken October 31, 2006)
The picture shows an extraordinarily colorful parhelion in a thin veil of cirrus clouds. Parhelia are among the most commonly observed halos; refraction of the sunlight in small, hexagonal ice cristals in the clouds are responsible for this atmospheric phenomenon. The picture was taken on the early morning of October 31, 2006, from Munich, Germany. (subm. to EPOD 2006-11-15, accepted by EPOD Dec.2006)
Evolution of an auroral substorm. Left: This extremely dynamic auroral display was observed from Northern Finland on 14.03.2004 02:29 EET. In contrast to the preceeding rather static auroral arcs, the structures seen during the here depicted substorm were moving and changing almost fluid-like. Right: The display was succeeded by pulsating aurora (14.03.2004, 03:28 EET), a type of aurora which fills parts of the sky with pale light patches appearing and disappearing independently of each other on a timescale of few seconds. While the visual impression is stunning, pulsating aurorae are rather hard to photograph due to their relative dimness and short appearance. [pictures: 3031, 3078 - weblinks: here and here] (subm. to APOD 2006-10-08, to EPOD 2007-03-22, accepted by EPOD 2007-03-24)
Glaciers are abundant in South-central Alaska's Prince William Sound. One showcase glacier is Surprise Glacier, whose bluish ice formations are seen in the picture. Is glacier ice really blue? No, it just appears to be blue: While the red part of white light is absorbed by the ice, the blue light is transmitted and scattered. The longer the light travels in ice, the more blue it appears. In contrast to ice, light does not penetrate far into snow, thus snow appears white.
(subm. to EPOD 2007-06-01, accepted by EPOD 2007-06-02)
The fact that the celestial sphere is rotating (or more accurately, of course, that the Earth is), can be seen when observing long-term exposures of the sky. In particular close to the celestial equator, rather dramatic star-trail pictures like this one captured during almost 3 hours at the Soelden ski resort (2700 m asl), gives a impression of the apparent motion of celestial sphere. The effect comes about as the celestial equator, a plane dividing the celestial sphere in a Northern and a Southern half, passes right through the constellation of Orion, which is seen in the lower center of the picture.
(subm. to EPOD 2007-08-28, accepted by EPOD 2007-08-29)