NASA reveals first topographic map of Titan


    In a major breakthrough in the world of astronomy, a team of scientists from NASA has successfully created the first global topographic map of Titan, the largest of Saturn’s natural satellites and the only moon in the solar system with a dense atmosphere.

    The map that has been published as part of a paper in the journal Icarus, would provide the researchers a valuable tool for learning more about the moon that has a lot of Earth-like features besides being one of the most and interesting worlds in the solar system owing to its geological and hydrological processes along with the complex weather systems.

    Titan has raised the interest of the scientists since it is the only moon in the solar system that has clouds, surface liquids and a mysterious, thick atmosphere. The cold atmosphere is mostly nitrogen, like Earth’s, but the organic compound methane on Titan acts the way water vapor does on Earth, forming clouds and falling as rain and carving the surface with rivers. Organic chemicals, derived from methane, are present in Titan’s atmosphere, lakes and rivers and may offer clues about the origins of life.

    The topographical map of Titan’s surface was prepared by using radar measurements with the help of NASA’s Cassini spacecraft. By decoding more about the surface of this smoggy moon, the scientist would gain an invaluable understanding of how it works and what processes are occurring on its surface. It may be recalled that a similar kind of project was undertaken for Mars using the Mars Global Surveyor (MGS).

    Speaking about the discovery, Ralph Lorenz, who led the Cassini radar team based at the Johns Hopkins University Applied Physics Laboratory, said: “Titan has so much interesting activity – like flowing liquids and moving sand dunes – but to understand these processes it’s useful to know how the terrain slopes. It’s especially helpful to those studying hydrology and modeling Titan’s climate and weather, who need to know whether there is high ground or low ground driving their models.

    Steve Wall, the deputy team lead of Cassini’s radar team, based at NASA’s Jet Propulsion Laboratory in Pasadena, California, said: “With this new topographic map, one of the most fascinating and dynamic worlds in our solar system now pops out in 3-D. On Earth, rivers, volcanoes and even weather are closely related to heights of surfaces – we’re now eager to see what we can learn from them on Titan.”

    Talking how the conclusions were drawn, Lorenz said that the team used a mathematical process called splining – effectively using smooth, curved surfaces to “join” the areas between grids of existing data.

    The most recent data used to compile the map is from 2012 with the chances of getting a revision when the Cassini mission ends in 2017, as the additional data accumulated will fill some of the gaps in present coverage.

    However, the project has its own set of challenges. Speaking about the same Lorenz said:. “Cassini isn’t orbiting Titan. We have only imaged about half of Titan’s surface, and multiple ‘looks’ or special observations are needed to estimate the surface heights. If you divided Titan into 1-degree by 1-degree [latitude and longitude] squares, only 11 percent of those squares have topography data in them.”

    Titan is Saturn’s largest moon – with a radius of about 1,600 miles (2,574 kilometers) and is surprisingly flat, with the topographic range (i.e. the range from the highest point to the lowest point) of just 2.5 kilometers (1.5 miles). The highest point on the surface of the entire moon is only about half a kilometer above the average.

    Further Titan’s thick haze scatters light in ways that make it very hard for remote cameras to “see” landscape shapes and shadows, the usual approach to measuring topography on planetary bodies. Virtually all the data we have on Titan comes from NASA’s Saturn-orbiting Cassini spacecraft, which has flown past the moon nearly 100 times over the past decade.