Earth & Environmental Sciences Blogs

Introduction Petra was founded in the 4th century BC by the Nabataean Arabs and was known in Arabic as Sila'a, Ar Rakeem, or biblically as 'Rqm,' all of which imply 'carved in the rock.' The Romans captured the site in AD 106, and it was dubbed Petra in Greek, or Al Betra in Arabic, both of which mean "carved in the rock." Several earthquakes are thought to have wreaked havoc on Petra, leading to its total ruin and eventual exodus in the 6th century AD. Figure 1  The Kasneh (Treasury) shining in the sun at the end of the long dark canyon known as the Siq – surely one of the most impressive and iconic sights in the world. Source: Anne Whaley Sousou. Locality Petra is situated in the middle of southern Jordan's rugged desert, halfway between the Red Sea and the Dead Sea, but it was also next to an ancient highway leading eastwards from the high plateau to Wadi Araba. The site is also accessible from Ma'an, which is located to the east. Abu Mous...

  Figure 1 Perspective view of crater with water ice at Martian north pole. Due to the low atmospheric pressure on Mars' surface, liquid water can only exist at the lowest elevations for short periods of time. Water appears to make up the majority of the two polar ice caps. If the water ice in the south polar ice cap were to melt, it would cover the entire planet's surface to a depth of 11 meters. The permafrost mantle reaches from the pole to around 60 ° latitude. Large amounts of water ice are believed to be trapped within Mars' thick cryosphere. Radar images from Mars Express and the Mars Reconnaissance Orbiter reveal huge amounts of water ice at both the poles and mid-latitudes from July 2005 to November 2008. On July 31, 2008, the Phoenix lander took a direct sample of water ice in shallow Martian soil. Figure 2  The north pole of Mars at the summer solstice, as seen in an image shot by the European Space Agency's Mars Express in May 2010. Landforms visible on Ma...

  Figure 1 Famous micrograph of Mars meteorite ALH84001 shows structures that resemble fossils, but most scientists regard them as mineral formations. Perseverance seeks less ambiguous evidence. NASA/JSC Allan Hills 84001 (often abbreviated ALH84001) is a meteorite discovered by a team of US meteorite hunters from the ANSMET project on December 27, 1984, in Allan Hills, Antarctica. ALH84001, like the other SNCs (shergottite, nakhlite, and chassignite), is assumed to be from Mars. It does not, however, fit into any of the previously identified SNC groupings. It weighed 1.93 kilos when discovered (4.3 lb). It made headlines throughout the world in 1996 when scientists stated that carbonate globules found there might include evidence for minuscule remains of Martian microorganisms. This rock is thought to be one of the Solar System's oldest parts, having crystallized from molten rock 4.091 billion years ago. It is considered to have evolved on Mars during a period when liquid w...

Malacology Chitons, clams, mussels, snails, sea slugs, tusk shells, octopus, and squid are among the mollusks studied in malacology. Mollusks can be found practically anywhere, including on the rocky shore, in freshwater settings, and in your own backyard. Characteristics Molluscs have the following characteristics: a soft, unsegmented body with a muscular foot or tentacles and a mantle capable of secreting a shell. Mollusks in general, but not all, have: a radula is an interior or external shell (tongue with teeth). Introduction With at least 50,000 live species, mollusks are one of the most diverse animal groupings on the world (and more likely around 200,000). Snails, octopuses, squid, clams, scallops, oysters, and chitons are among the species found there. Mollusca also includes several lesser-known families, such as the monoplacophorans, which were assumed to be extinct for millions of years until a specimen was discovered in the deep water off the coast of Costa Rica in...

Lunar water may be more accessible than previously assumed, according to new Moon observations. The new information is especially interesting for NASA, which intends to use the Moon's resources particularly water ice embedded in the soil to aid future astronauts in living and working on the lunar surface. Researchers discovered water directly on the lunar surface in one investigation, discovering the molecule on portions of the Moon that were lit by the Sun. According to a second study, water ice could be stored in tiny pockets or small craters strewn across the Moon's surface, making water possibly more abundant and accessible than we could have thought. Both studies were published in the journal Nature today. It's not the first time that water has been discovered on the Moon. However, the only water we've been able to locate and verify thus far is quite difficult to access. It appears to be mostly found in perpetually shadowed huge craters at the lunar South Pole....

Recovery of Gas Hydrates We can recover gas hydrates through various methods; Thermal Stimulation Method. Depressurization Method. Inhibitor Injection Method. Carbon Dioxide Injection Method. Thermal Stimulation Method The thermal stimulation approach involves raising the hydrate temperature above the stability point, causing the hydrate to dissociate. Thermal stimulation requires a continuous energy source to overcome the endothermic heat of dissociation. Figure 1 Thermal injection method. Depressurization Method Depressurization involves lowering the hydrate pressure below the stability point, causing the hydrate to dissociate. Depressurization results in rapid hydrate dissociation, but with an associate drop in the hydrate temperature. Without an external heat source, depressurization lowers the hydrate temperature to a new equilibrium condition, halting the depressurization process. Figure 2 Depressurization method. Disadvantages There are the following dis...

Chile's Atacama Desert, which stretches from the Pacific Ocean to the Andes Mountains, is a sparsely populated, almost rainless plateau. It is less than 100 miles wide on average, yet it stretches 600 miles south of the Peruvian border. The Pacific Coastal Range, with an average elevation of 2500 feet, is the mountain range closest to the ocean. East of the Andes Mountains is the Cordillera Domeyko, a range of foothills. Salt basins (salars), sand, and lava flows make up the Atacama. The scenery is regarded as "moon-like" since it is so bleak. In reality, the Atacama Desert has been considered as a suitable location for testing a future lunar rover prototype. Figure 1  (a) Current climatic zones of western South America. SA stands for Salar de Atacama. (b) Morphotectonic subdivisions of the Central Andes. Geology & geochemistry The Atacama Desert, the world's driest, has a number of geological and geochemical characteristics that set it apart from any other habi...