"Floods, drought, climate change, and even war are all directly related to the fate of humble dirt. Made from the same elements as stars, plants, and human beings, dirt is very much alive. One teaspoon of dirt contains a billion organisms working in balance to sustain a series of complex, thriving communities that are invisibly a part of our daily lives. DIRT! The Movie tells the story of Earth’s most valuable and underappreciated source of fertility — from its miraculous beginning to its tragic degradation. This insightful and timely film tells the story of the glorious and unappreciated material beneath our feet.Narrated by Jaimie Lee Curtis and inspired by William Bryant Logan’s acclaimed book Dirt: The Ecstatic Skin of the Earth, DIRT! The Movie introduces viewers to dirt’s fascinating history. Four billion years of evolution have created the dirt that recycles our water, gives us food, and provides us with shelter. But humanity has endangered this vital living resource with destructive methods of agriculture, mining practices, and urban development, with catastrophic results: mass starvation, drought, and global warming."
An avalanche on Mars captured by the HiRISE camera on the Mars Reconnaissance Orbiter on November 27, 2011.
Supercomputer simulation showing the tangled magnetosphere surrounding Earth.
Limestone is a sedimentary rock whose chief mineral component is calcite (calcium carbonate: CaCO3). Limestone can be formed by precipitation of calcite dissolved in water or by depostion of marine organisms and entrainment of secondary minerals. Approximately 80 to 90% of limestone composition are skeletal fragments of marine organisms such as coral or foraminifera.
Some other carbonate grains comprising limestones are soil types such as ooids, peloids, intraclasts, and extraclasts; moreover, certain limestones do not consist of grains at all, but rather and are formed completely by the chemical precipitation of calcite or aragonite, the latter also known as travertine.
Due to the ease of dissolution and precipitation processes of calcium carbonate, limestone occurrences are linked to fascinating topographic phenomena of cave, karst and limestone pavements, the latter often called alvar.
Credit: NASA/SSAI, Hal Pierce
NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
"Buried treasure on Mercury? If so, I’d look here first. This image shows a currently unnamed crater with an “X” emblazoned on it. The perpendicular lines that cross the crater are secondary crater chains caused by ejecta from two primary impacts outside of the field of view, according to MESSENGER scientists. MESSENGER has been in orbit of Mercury since mid-March of this year, and its Mercury Dual Imaging System (MDIS) pivot and Narrow Angle Camera (NAC) spotted this unusual landform. MESSENGER will be mapping more than 90% of Mercury’s surface as part of a high-resolution surface morphology base map that will be created with MDIS."
"Although they aren’t particularly fond of the comparison, scientists from the GOCE satellite team had to admit that new data showing Earth’s gravity field – or geoid — makes our planet look like a rotating potato. After just two years in orbit, ESA’s sleek and sexy GOCE satellite (Gravity Field and Steady-State Ocean Circulation Explorer) has gathered sufficient data to map Earth’s gravity with unrivalled precision. While our world certainly doesn’t look like a spinning tuber, this exaggerated view shows the most accurate model of how gravity varies across the planet."
"Composed of large, white, sweeping dunes, at first glance Lençóis Maranhenses looks like an archetypal desert. In fact it isn't actually a desert. Lying just outside the Amazon basin, the region is subject to a regular rain season during the beginning of the year. The rains cause a peculiar phenomenon: fresh water collects in the valleys between sand dunes, spotting the desert with blue and green lagoons that reach their fullest between July and September.
The area is also surprisingly home to a variety of fish which, despite the almost complete disappearance of the lagoons during the dry season, have their eggs brought from the sea by birds."
Lightning erupts from the crater of Mount Shinmoedake on the island of Kyushu in Japan.
© Reuters New Agency