#lonar

So, what made scientists change their mind about the crater? First of all, the rocks beneath lonar crater were found to contain maskelynite, a naturally occurring glass that forms during extremely high-velocity impacts as feldspare minerals are shocked. Also, deformed basalt layers, non-volcanic ejecta surrounding the crater, shatter cones, and shocked breccia inside the crater all indicated that the crater was formed in an asteroid impact. Basaltic rocks are some of the most common in the solar system, found on the floor of the oceans, at the surface of the other rocky planets, asteroids, and even moons such as Io. Since basalts are rare on Earth’s continents, scientists have studied Lonar Crater’s structure to better understand how impacts reshape the surfaces of basalt-rich worlds. There has been debate about the timing of the impact. One type of dating based on heating various minerals suggested the crater formed 50,000-35,000 years ago. However recent Argon-argon dating proposes a date of 656,000 years old. The latter ages based on isotopic measurements seem most reliable, since erosion of the crater also indicates an older age; the younger ages may reflect re-heating of the site by wildfires or even by exposure to the sun. The saltwater lake that fills Lonar crater is about 150m deep. In the middle the water has a pH of 10.5 and thus is highly alkaline. Here, we find unusual microorganisms that can only survive in these highly alkaline environments. Near the shores the water is less saline due to the presence of small streams of freshwater. The normal blue-green color of the lake is caused by blue green algae, which typically survive well in the lake because of its salinity and alkaline chemistry. This year has been particularly dry and warm at the crater site, allowing for extra evaporation that may have increased the salinity further, such that a different type of microorganism has taken over. Some types of bacteria and archaea create a type of β-carotene to protect themselves against exposure from the sun, and lakes where those organisms bloom commonly turn pink to red in the dry season. Samples of the waters from Lonar have been taken to various labs to determine what organisms have triggered the color change this year. In addition, the crater rim is known for its of acacia, teak and tamarinds trees in the otherwise dry and barren landscape. The crater is surrounded by 12 temples, of which a large number lie in ruins and are now inhabited by bats and monkeys. -OW/JBB- Image: Satellite image of Lonar crater. https://bit.ly/2YwFnzF Today’s pink color: https://www.reddit.com/r/interestingasfuck/comments/h7ckur/the_water_in_the_lonar_crater_lakeindia_has/ References: http://www.princeton.edu/geosciences/people/maloof/research/lonar.xml http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1661.pdf http://earthobservatory.nasa.gov/IOTD/view.php?id=8654