An image of Death Valley overlaid with digital topography data from the ASTER Global Digital Elevation Model

The most complete terrain map of the Earth’s surface has been published by the US and Japan. The resulting Global Digital Elevation covers 99% of the planet’s surface.

Earth is the third palnet of the solar system fron the sun and the largest of the terrestial planets int the solar system in terms of diameter , mass and density. According to study, it is the only place in the universe where life is known to exist, it is the home to millions of species including humans. The earth’s terrain varies greatly from place to place and the planetary surface undergoes reshaping over geological time periods due to the effects of tectonics and errosion. The surface features built up or deformed through plate tectonics and are subject to steady weathering and precipatation, thermal cycles, and chemical effects, glaciation, coastal errosion, the build-up of coral reefs and the large meteorites impact also act to reshape the landscape. Ther is a new published most complete earth’s map and the detail is as follows. The data, comprising 1.3 million images, come from a collaboration between the US space agency Nasa and the Japanese trade ministry. The images were taken by Japan’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster) aboard the earth-monitoring Terra satellite.

The Terra satellite, dedicated to Earth monitoring missions, has shed light on issues ranging from algal blooms to volcano eruptions. For the Aster measurements, local elevation was mapped with each point just 30m apart. “This is the most complete, consistent global digital elevation data yet made available to the world,” said Woody Turner, Nasa programme scientist on the Aster project. “This unique global set of data will serve users and researchers from a wide array of disciplines that need elevation and terrain information.”

Previously, the most complete such topographic map was Nasa’s Shuttle Radar Topography Mission, covering 80% of the Earth’s surface. However, the mission’s results were less accurate in steep terrain and in some deserts. Nasa is now working to combine those data with the new Aster observations to further improve on the global map. Terra was launched in December 1999 as part of NASA’s Earth Observing System (EOS). The three EOS platforms are part of NASA’s Science Mission Directorate and the Earth-Sun System that observe, understand, and model the Earth system to find out the way it is changing and thereby better predict changes.