Friday, January 14, 2005
We Probe Titan
The European Space Agency has, this morning, reported that a “carrier tone” signal detected by the Robert C. Byrd Green Bank Telescope in West Virginia between 11:20 and 11:25 CET (5:20-5:25am EST) indicates that the Huygens probe “is alive” within the atmosphere of the Saturnian moon Titan.
According to the ESA, the detection of the carrier signal:
Indicates that the back cover of Huygens must have been ejected, the main parachute must have been deployed and that the probe has begun to transmit…This, however, still does not mean that any data have been acquired, nor that they have been received by Cassini. The carrier signal is sent continuously throughout the descent and as such does not contain any scientific data.
Substantive datasets, including images from the probes DISR (Descent Imager Spectral Radiometer), are expected via a relay through the Cassini mother ship at the European Space Operations Center later this afternoon.
According to the New York Times:
ESA's science director, David Southwood, said the mission had successfully passed a difficult and critical step. ``We didn't promise we could do this. We were pushing the limit just to do this.”
The Huygens descent is expected to take 2 ½ hours through a nitrogen and methane atmosphere that is 1 ½ times thicker than Earth’s atmosphere.
Scientists do not know what to expect when Huygens hits the surface of Titan at 20 kilometers per hour but have prepared the probe for a liquid or hard landing and, at best, expect at least 3 minutes of transmission time from the moon’s chemically corrosive surface.
Images: Lawrence Livermore Labs (Keck Telescope), ESA