Thursday, November 13, 2008

CHANDRAYAAN-1: MISSION ACCOMPLISHED


Chandrayaan reached the final resting orbit, about 100 kms from the moon on 12th November 2008. Chandrayaan will remain in this orbit for the next two years. During its remaining lifetime of 2 years, the terrain mapping camera will make a detailed study of the moon's surface to create a three dimentional map of the moon. It will also search for minerals and ice.

ISRO has carried out three orbit-lowering moves since the spacecraft entered the lunar orbit on 8th November. The spacecraft, which was launched on October 22, was propelled on its 4,00,000-km voyage to the moon in a number of stages, with its orbit being raised progressively towards the moon by activating its liquid motor.

The tricolour landed on the Moon at 8.31 pm on 14th November, opening a new chapter in the history of India’s space exploration.The tricolour was painted on all sides of the 29 kg Moon Impact Probe (MIP) which was attached to the top portion of the main lunar orbiter, Chandrayaan. The MIP is the brainchild of former President A P J Abdul Kalam who witnessed its separation from the main orbiting craft and its crashlanding 32 km from the Shackleton crater on the moon’s south pole from the mission control room at ISRO’s telemetry, tracking and command network (ISTRAC) in Bangalore.

During its flight, its video camera took pictures of the Moon, the spectrometer began its analysis and the altitude meter did what is known as a ranging. While approaching the Moon, it slowed down slightly, then spun. While spinning, its three instruments went into action. When it was 5 km above the Moon’s surface, the altimeter did the ‘ranging of the Moon’. ‘‘All this while the atmosphere was pretty tense in the mission control room,’’ said a scientist.

Other entities which have reached the Moon are the US, former Soviet Union, Japan (albeit via a malfunction that sent its orbiter crashing onto the lunar surface) and the European Space Agency (17 nations). India becomes the fifth member of this club.

Saturday, November 8, 2008

INDUS VALLEY CIVILIZATION

The earliest traces of civilization in the Indian subcontinent are to be found in places along, or close, to the Indus river. The greater Indus region was home to the largest of the four ancient urban civilizations of Egypt, Mesopotamia, South Asia and China. It was not discovered until the 1920's. Excavations first conducted in 1921-22, in the ancient cities of Harappa and Mohenjodaro, both now in Pakistan, pointed to a highly complex civilization that first developed some 4,500-5,000 years ago, and subsequent archaeological and historical research has now furnished us with a more detailed picture of the Indus Valley Civilization and its inhabitants. Most of its ruins, even its major cities, remain to be excavated.

Many questions about the Indus people who created this highly complex culture remain unanswered, but other aspects of their society can be answered through various types of archaeological studies.

There seems to have been another large river which ran parallel and west of the Indus in the third and fourth millenium BCE. This was the ancient Saraswati-Ghaggar-Hakra River (which some scholars associate with the Saraswati River of the Rig Veda). Its lost banks are slowly being traced by researchers by various modern techniques of satellite imagery. Along its now dry bed, archaeologists are discovering a whole new set of ancient towns and cities.

Harappa was a city in the Indus civilization that flourished around 2600 to 1700 BCE in the western part of South Asia.
Mohenjo Daro, or "Mound of the Dead" is another famous ancient city of the Indus Valley Civilization that flourished between 2600 and 1900 BCE. It was one of the first ancient cities in the world. The site was discovered in the 1920s and lies in Pakistan's Sindh province. Only a handful of archaeologists have excavated here, described in the introduction and illustrated essay Mohenjodaro: An Ancient Indus Valley Metropolis. The excavation at Mohenjo-daro was led by Rakhal Das Banerjee, E. J. H. MacKay, and Sir John Marshall.

The Indus Valley people were most likely Dravidians, who may have been pushed down into south India when the Aryans, with their more advanced military technology, commenced their migrations to India around 2,000 BCE. Though the Indus Valley script remains undeciphered down to the present day, the numerous seals discovered during the excavations, as well as statuary and pottery, not to mention the ruins of numerous Indus Valley cities, have enabled scholars to construct a reasonably plausible account of the Indus Valley Civilization.