Kilimanjaro Fireball
While an electric-lighted line of mountain climbers snakes toward it, a dazzling fireball (bright meteor) streaks over Tanzania’s Mount Kilimanjaro (the summit of Kibo at 5893 meters). — Kwon, O Chul
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Volcanic Field Star Trails
A long exposure image captured the rotating sky above Karapinar volcanic field located in central Anatolia, Turkey. The basaltic volcanic field consists of several volcano cones and craters. — Gernot Meiser
Aeon Rising
The Milky Way rises beyond Utah’s iconic Delicate Arch. — Brad Goldpaint
Ventana del Diablo (Cuenca-España) — © Dani Caxete
Polygons are of great interest because they often indicate the presence of shallow ice or of desiccation such as in a mud flat. However, nature sometimes seems too clever for us.
Polygons form by the intersecting ridges of sand dunes. If this deposit were to become indurated and eroded, we might not be able to tell that they originated as wind-blown dunes, and interpret the polygons as evidence for a dried-up lake, for example. Dunes often accumulate in the bottoms on craters, also a good setting for a (temporary) lake.
The illumination is coming from the upper left, so the bluish ridges are high-standing.
Milky Way Below Sea Level
“The photo shows the Milky Way just after twilight from the salt flats of El Gualicho in Patagonia, Argentina. Altitude is 72 meters below sea level. The Milky Way was visible to the naked eye even when the the sky was not totally dark yet. There’re hundreds of stars reflected on the salt too.” — Luis Argerich
Devils Tower Milky Way and Aurora
“Shooting the Milky Way in the early hours of 5/7/2013, It was a spectacular night for stargazing. Upon editing I realized I caught some very faint red Aurora on the horizon and also a satellite that grazes the top of Devils Tower.” — Brennan Jontz
Yellowstone National Park’s Prismatic Pool
The photo above shows the brightly colored Grand Prismatic Spring in Yellowstone National Park, Wyoming. The red and yellow colors of the pool in the foreground contrast sharply with the azure blue color in the mid-ground and with the greens and tans of the slope in the background.
Red and yellow colors are caused by pigmented bacteria and thermophiles (heat-loving algae) inhabiting the hot spring. Specific colors of the thermophiles correspond to a particular temperature range of the naturally heated springs – temperatures are 160 F (70 C) at the spring’s source.
Colors are also a result of the ratio of chlorophyll to carotenoids – red/orange is observed during summer but typically, dark green is favored during the colder months. The inset photo shows a close up of a thermophile colony.
Africa. The world’s greatest wilderness. The only place on earth to see the full majesty of nature. There’s so much more here than we ever imagined.
Logas Beach on Corfu Island, Greece
The photo above features sedimentary layering at Logas Beach, Peroulades (northern Corfu Island), Greece.
It was taken in the early evening of March 23, 2013 — the landscape is brightened by the waxing, gibbous Moon and by a long exposure. The cliff strata here consist primarily of clay deposits with sand lenses separating the clay.
At a number of locations along this beach, wind and waves have undercut the cliff face. Note the structures atop the cliff (upper right), lurking precariously close to the edge.
This image covers many shallow irregular pits with raised rims, concentrated along ridges and other topographic features. How did these odd features form?
One idea is that they could be from sublimation of shallow lenses of nearly pure ice, but why do the pits have raised rims? They can’t be impact craters with such fortuitous alignment and irregular margins. They aren’t wind-blown deposits because there are many boulders, too big to be moved by the wind. There are younger wind-blown drifts on top of the pits, and there’s no clear connection to volcanism.
Some speculate that there were ancient oceans over this region—could that somehow explain these features? Ancient glaciation is another possibility, perhaps depositing ice-rich debris next to topographic obstacles.Future images of this region may provide clues, but for now this is a mystery.
Sporadic eruptions from Paluweh Volcano have been sending ash and volcanic gases into the air since late 2012. This natural-color image was acquired by the Advanced Land Imager (ALI) on the Earth Observing-1 (EO-1) satellite on April 19, 2013.
A Dali watch on an alligator wristband - Mexico.
Chondrites are stony meteorites. They’re the most common and probably the most fascinating type of meteorite. The meteor/meteorite that broke windows in the Russian city of Chelyabinsk this past February was a stony chondrite.
The composition of chondrites is very similar to the composition of the Sun, except that they’re lacking hydrogen and helium. So, if you’d like to hold a piece of the Sun in your palm, chondrites are about as close as you can get. Their name is derived from the chondrules (spherical inclusions) observed in most of them. Chondrules are only found in meteorites.
They’re over 4 billion years old — older than the Earth and other planets. Scientists previously identified meteorites by the crystals found within chondrules, but later they realized that chondrules may recrystallize during weathering processes once they reach the Earth’s surface. Sometimes a broken face of a meteorite is weathered in such a way that 3-D chondrules are seen (above at upper right corner). However, chrondules can be more easily studied by cutting the parent chrondite into slices. Shown at center is a a microscopic image of a 3 cm slice of a chondrite that was found in northwest Africa. — Mila Zinkova
