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Shoreline on Titan?

Shoreline on Titan?

The Cassini Radar (RADAR) takes pictures like a camera but it "sees" using microwaves instead of light. It measures how objects reflect microwaves, which tells scientists something about how rough they are, or how they would conduct electricity. All this information helps scientists deduce what a celestial body's landscape looks like and figure out its composition.

Another great feature of radar is that it can pierce through an atmosphere, even one as thick and murky as the one engulfing Titan. By bouncing radio signals off Titan's surface and timing their return, the RADAR is producing maps of Titan's surface and measuring the height of surface objects such as mountains and canyons.

Stephen Wall
Stephen Wall

"We have pictures of Titan that look unbelievably like Earth -- there are things that look like rivers, lakes, mountains, craters, and maybe even volcanoes," says Steve Wall, deputy RADAR team leader. "Considering that Titan is a lot colder than Earth, that's pretty amazing!"

Team members like to call the instrument the "Titan Radar Mapper" because it was built especially to study Titan. But the instrument is also providing valuable information when pointed at Saturn, its rings and at other moons orbiting the ringed planet.

Perhaps one day it may even uncover the extraordinary.

Titan Mosaic
Titan Mosaic

"Who knows, maybe there are aliens out there somewhere that don't see like we humans do, but more like the RADAR does!" Wall jokes.

In the meantime, at the end of Oct. 2005, Cassini will fly over a very special area of Titan -- and the RADAR team will be particularly busy.

"We will take radar pictures of the same place the Huygens probe landed," Wall says. "That will help us to understand the area where the probe landed."

For more information, see the engineering technical write-up.

At a Glance

Radio Detection and Ranging Instrument (RADAR) on the spacecraft
RADAR on the Cassini Spacecraft

Radar (an acronym that stands for "radio detection and ranging") can operate in three ways: imaging, altimetry and radiometry. Each mode allows for the collection of different types of data, from straightforward imaging to 3-dimensional modeling to passive collection of information, such as simply recording the energy emanating from a planet's surface.

RADAR Sensing Instruments:

  • Synthetic Aperture Radar Imager [SAR] (13.78 GHz Ku-band; 0.35 to 1.7 km resolution)
  • Altimeter (13.78 GHz Ku-band; 24 to 27 km horizontal, 90 to 150 m vertical resolution)
  • Radiometer (13.78 GHz passive Ku-band; 7 to 310 km resolution)

RADAR Instrument Characteristics:

  • Mass (current best estimate) = 41.43 kg
  • Peak Operating Power (current best estimate) = 108.40 W
  • Peak Data Rate (current best estimate) = 364.800 kilobits/sec