ESA Promises Much More New Information
One week after the successful completion of Huygens’
mission to the atmosphere and surface of Titan, the largest and
most mysterious moon of Saturn, the European Space Agency is
bringing together some of the probe’s scientists to present
and discuss the first results obtained from the data collected by
the instruments.
After a 4 billion kilometer journey through the Solar System that
lasted almost 7 years, the Huygens probe plunged into the hazy
atmosphere of Titan at 11:13 CET on January 14 and landed safely on
its frozen ground at 1345 CET. It continued transmitting from the
surface for several hours, even after the Cassini orbiter dropped
below the horizon and stopped recording the data to relay them
towards Earth. Cassini received excellent data from the surface of
Titan for 1 hour 12 minutes.
More than 474 megabits of data were received in 3 hours 44
minutes from Huygens, including some 350 pictures collected during
the descent and on the ground, which revealed a landscape
apparently modelled by erosion with drain channels, shoreline-like
features and even pebble-shaped objects on the surface.
The atmosphere was probed and sampled for analysis at altitudes
from 160 km to the ground, revealing a uniform mix of methane with
nitrogen in the stratosphere. Methane concentration increased
steadily in the troposphere down to the surface. Clouds of methane
at about 20 km altitude and methane or ethane fog near the surface
were detected.
The probe’s signal, monitored by a global network of radio
telescopes on Earth, will help reconstruct its actual trajectory
with an accuracy of 1 km and will provide data on Titan’s
winds. Early analysis of the received signal indicate that Huygens
was still transmitting after 3 hours on the surface. Later
recordings are being analyzed to see how long Huygens kept
transmitting from the surface.
Samples of aerosols were also collected at altitudes between 125
and 20 km and analyzed onboard. During the descent, sounds were
recorded in order to detect possible distant thunder from
lightning, providing an exciting acoustic backdrop to
Huygens’s descent.
As the probe touched down at about 4.5 m/s, a whole series of
instruments provided a large amount of data on the texture of the
surface, which resembles wet sand or clay with a thin solid crust,
and its composition, mainly a mix of dirty water ice and
hydrocarbon ice, resulting in a darker soil than expected. The
temperature measured at ground level was about -180 degrees
Celsius.