Astronomy is as old as any science. In olden days it was of great importance. Many ancient civilizations of old age like Egyptian, Chinese, Indian, Greek civilization contributed largely.
In India scientists like Aryabhatta, Varahmihir contributed largely to this old science of astronomy. The King of Jaipur, Sawai Jaisingh II built Jantarmantar ( meaning Instruments and Formulae’s in many cities of India ) Instruments such as sundials, an instrument used to determine sun’s altitude and position of equinoxes & solstices, an instrument which measures the alt. and azim. of heavenly body to high accuracy .
India is also very fortunate to have some nature - built structures near the famous Ajantha and Ellora caves in India a small place called LONAR in Buldhana District Maharashtra is present. This is a Meteor Impact Crater which has salty water in it.
Some 52,000 years ago a huge piece came from the space and hit the surface of LONAR with the impact of 6 Mega Tonne bombs , creating a crater of about 1830 meters in diameter and 150 meters deep. Such impact would have been have caused by a 60 meters long and 2 million tonnes heavy Meteor.
These craters are caused by Meteors which are lurking in the space and crash onto some planets. These craters are very similar to that of volcanic craters . When the magma from volcano flows out, a layer of lava is formed.
The area in which the crater is situated is a plateau ( Deccan Plateau ) which is caused by volcano . This process is a slow and very long one, but the crater which is formed is just 40,000 to 50,000 years ago which cannot be a volcanic crater. This was proved by Geological Survey of India and Smithsonian Institute (America ).
A new theory of formation which was proposed was of vertical subsidence of the ground . The LONAR crater has water in it is the biggest meteoric crater which has BASALT in it and has water in it . The lake is deep and one cannot make out whether it is a crater until one comes to the edge of crater . The crater has a large slope and there is a dense forest in this region. The two slopes within the crater out of that one is of 15 to 18 degrees while the other one measures of 30 degrees. This shows that it is a Meteor crater e.g. when a metal ball is thrown in sand in a certain direction in which the ball hits the sand gets little small while the opposite side to it increases. The slope measuring 15-18° has a notch through which the meteor came. The opposite side of slope increases due to the pressure created by the meteor and by the remains of the notch side blown away .
The water in the crater is very salty. It is 10 times saltier than drinking water (pH = 10.5 ). Salts and Minerals like sodium, chloride, carbonates, flourides and bicarbonates are found. These are found by the small streams of water joining the crater. Then streams bring water as well as salts and minerals with them. But as this water does not drain away these substances get collected beneath the surface. Some 4 years back , water from the Lonar lake had evaporated . The villagers witnessed some crystalline form of these salts and minerals. In such conditions one cannot think of any living organisms. But microorganisms like Arthorospira and algae are found abundant. We also found Spirullina, Closterium, Chlorella, Eudorina and Ankistrodesmus in the water. Various bacteria’s are also presnt.Algaes are found in abundant near the sides of lake.Distinct layers of Dried Algae, Green Algae and Newly forming Algae are seen .
The detail study of Lonar crater gave the following results and most of them proved that this was indeed a meteor impact crater. Detail study and drill holes dug by Geological Survey Of India and Smithsonian Institute. The Lonar crater has been proved to be caused by an aerolite meteor ( it contains mainly rocky material ) because no metal fragments have been found strewn around the crater. Unlike volcanic crater, meteor craters show signs of being subjected to severe shock waves. As a result of impact of meteorite and the shock , rocks at the surface undergo change (impact or shock metamorphism ). The impact also produces high temperatures and pressures, certain new minerals are formed , often rocks are get melted and turn into a glassy material . These materials would be naturally scattered around the crater .
The drill hole come across sediments coarse breccia glass and then bedrock (The rocks which are broken into small angular fragments when consolidated are known as BRECCIA ).
Samples drilled form a large brought forth MASKELNITE a glass like mineral , MASKELNITE is not found in the natural form on the Earth but laboratory experiments have shown that it is produced when plagioclase felspar ( a common rock - forming mineral ) is subjected to a shock .
MASKELNITE was found in coarse BRECCIA with small conical shaped stone & micro BRECCIA with moderately shocked fragments in the drill holes .
The Lonar lake can be compared with craters on moon. Specimens of stone brought by Apollo astronauts are very similar to that of found in Lonar .Microbreccia, Glass Beads and brown spherules of Lonar resemble to that of craters on Moon.
During the formation of Lonar lake the meteor broke into three pieces forming 3 craters. One known as Lonar and other two known as Ganesh Lake and Ambar Lake. These both have dried up and are not of much interest .
Lonar Lake is surrounded by many temples, about 14 temples are situated within the slope of Lonar. The oldest temple is some 1300 yrs old and many of them have fallen before. These temples are built by different kings of different religions. A temples has sculpture which tells about the formation of Lonar. A demon named Lavanasur had caused trouble on earth, earth requested Lord Vishnu to kill the demon. Lord said that while killing the demon he might destroy the earth. So he takes the form of a child and kills the demon. The demon goes deep into earth and dies. The name of the demon Lavanasur in Sanskrit language means ' salt ‘ . A hole was formed where later on lake was formed. This salty lake came to be known as Lonar ( or Lavanar - Demon Lavanasur ). During Holy Festivals people come in number of thousands to visit a temple where rituals take place. The temple is about 20-25 Mts. away from the Lonar Lake, people coming here throw plastic wastes and food stuffs near to the temple. Many people take bath in Lonar Lake polluting the lake. Many skin diseases are cured by this water . Other temples which are now in forests have been occupied by animals and bats .
Lonar crater is surrounded by dense forests. Many trees are found, birds such as Peacock, Black Drongo, Little Green Bee Eater, Shrike, Pipit, Crane, Hoopoe, etc. are found. Rabbit, Deer , Snake are seen here. Trees of Custard Apple, Eucalyptus, Lemon grass, Bamboo, Teak, and many trees were seen . It is a place with Rich ‘Bio-Diversity. ’
The crater has now world -wide recognition, few years ago plans of building a Hotel were made but they were rejected as they were considered to be harmful for the crater. Anyone can enter the lake and damage it, no security system is present. Farming is done near the crater causing considerable damage to the soil . Fertilizers mix with Lonar water as small streams meet this lake. The city development taking place is approaching towards the lake. Plastic wastes are put by people visiting the temples within the lake. The main threat is possessed by a lake placed in the village near to Lonar. The water from the lake situated in village evaporates and much of it goes in the crater, water seeps through soil and reaches Lonar crater. This results in increasing height of Lonar and losing its salinity.
This crater has a great importance in Geology and Astronomy. This place
has to be saved and preserved. Indians have started looking into
this matter which has to be more focussed and sharp. But it is important
visiting and studying this crater for a astronomy lovers.