The Huygens probe impacted Titan’s
atmosphere at 09:06 GMT Friday morning, with an expected landing on
Titan’s mysterious surface three hours later. This near-infrared image
(http://www2.keck.hawaii.edu/news/science/huygens/index.html) shows
Titan at the moment Huygens reached its target.
“Although no disturbances in Titan’s atmosphere were detected, the
observations provide the best images that characterize the satellite at
the moment of probe entry”, says Antonin Bouchez, a staff member at the
Keck observatory, who was leading the observing effort.
“It was worth getting up in the middle of the night for this historic
moment”, says Fred Chaffee, director of the Keck Observatory, “despite
the bad weather on the mountain”. Winds were blowing at 40-50 mph,
while the mountain top itself was still cloaked with snow and ice from
a recent storm. Other team members that particpated in the observations
were David LeMignant from the Keck Observatory, Imke de Pater, a
professor at the University of California at Berkeley, and Michael
Brown, a professor at Caltech.
Titan is of particular interest to scientists because it is the only
moon in our solar system with a dense, methane-rich, nitrogen
atmosphere, reminiscent of our own atmosphere here on Earth. The moon
is cloaked in a thick, smog-like haze produced by the breakup of
methane by sunlight. Further study of this moon could provide clues to
planetary formation and evolution and, perhaps, about the early days of
Earth as well.
To get a closer look at Titan, scientists from three different
international space agencies developed the Cassini-Huygens mission, a
spacecraft orbiter that arrived in Saturn’s orbit in July 2004 after a
seven-year voyage. The four-year mission will include 70 orbits around
the ringed planet with an array of instruments to study the planet, its
rings and its 30 known moons.
The Huygen’s probe detached from Cassini on Christmas Eve, Dec. 24th,
2004. The probe has since been falling to Titan and entered the
atmosphere shortly after midnight, local time on Friday morning (09:06
GMT) January 14, 2005. Three sets of parachutes were to slow the probe
and to provide a stable platform for scientific measurements.
Instruments on board will collect information about the atmosphere’s
chemical composition and the clouds surrounding Titan during its 2-2.5
hour descent. The data will be radioed to the Cassini orbiter, which
will then relay the data to Earth.
Near-infrared images were taken from the W. M. Keck Observatory with
the near infrared camera, NIRC2, and the adaptive optics system at the
time of probe entry. The team had planned imaging sequences to look for
thermal emissions or condensates at the probe entry site.
