The existence of lakes on Titan was discovered by NASA's Cassini probe a few years ago. Their radar instruments located, especially near the Titan North Pole, flat, well-defined locations whose reflection suggested a fluid surface. This made it clear that Titan is the first known celestial body outside the earth on which lakes exist.
But because the spacecraft Cassini does not orbit the Titan, but only occasionally flies by on its way through the Saturn system past him, there was so far no map of the moon, which shows its landscape forms at a glance. "Titan has so much interesting activity - flowing fluids, migratory sand dunes - but to understand these processes, we need to know what the terrain is like, " explains Cassini card manager Ralph Lorenz of Johns Hopkins University in New York Laurel. Because the course of rivers, the formation of clouds and generally the entire weather are strongly influenced by the elevations and depressions of the landscape. "Especially for researchers studying the hydrology and climate of the moon, it is important to know whether they should start with their models of flat or high altitude, mountainous terrain, " said Lorenz.
Lowering in the polar regions and mountains on the equator display
To facilitate the exploration of the Saturn moon, NASA researchers have now for the first time created a preliminary topographic map of the titanium surface. "We did not cover more than half of the surface and had to extrapolate in many places - but we felt we could not wait until 2017 when the Cassini mission ends, " the researcher explains. Therefore, they have decided to evaluate all the data collected from 2004 to 2012 and to create a map. At the sites where there was no data, the researchers used an algorithm that determined from the height of the surrounding data points what height of the ground at that location would most likely have.
"With this new topographic map, we are now seeing three of the world's most intriguing and dynamic worlds of our solar system for the first time, " said Steve Wall of the Cassini team at NASA's Jet Propulsion Laboratory in Pasadena. The map shows, among other things, that the polar regions of the moon are shallower and lower than the area around the equator. There, numerous mountains and plateaus line up, while in the far north and south depressions dominate. In the next few years, Cassini will fly past the Titan several times and will map piece by piece the not yet recorded areas of the moon. For the time being, however, this preliminary overview map already helps to model the climate and material cycles on the Titan more precisely and thus to better understand them.Ralph Lorenz (Johns Hopkins University, Laurel) et al., Icarus, doi: 10.1016 / j.icarus.2013.04.002 © science.de - === Nadja Podbregar