View over an alien world
Copyright: ESA/NASA/JPL/University of Arizona
At first glance, this scene may look like a reptilian eye or a
textured splash of orange paint, but it is actually a fish-eye view of
Saturn’s moon Titan. It was acquired at a height of about 5 km as ESA’s
Huygens probe, part of the international Cassini–Huygens mission,
descended through Titan’s atmosphere before landing.
In the late
afternoon of 14 January 2005, engineers and scientists at ESA’s ESOC
operations centre in Darmstadt, Germany, waited anxiously for data to
arrive from Huygens, which touched down on Titan at around 12:34 GMT –
the most distant landing of any craft.
Following its release from
NASA’s Cassini on 25 December, Huygens reached Titan’s outer atmosphere
after 20 days and a 4 million km cruise. The probe started its descent
through Titan’s hazy cloud layers from an altitude of about 1270 km at
10:13 GMT. During the following three minutes Huygens decelerated from
18 000 km/h to 1400 km/h.
A sequence of parachutes then slowed it
down to less than 300 km/h. At a height of about 160 km the probe’s
scientific instruments were exposed to Titan’s atmosphere. Around 120
km, the main parachute was replaced by a smaller one to complete the
descent.
The probe began transmitting data to Cassini four minutes
into its descent and continued to transmit after landing at least as
long as Cassini was above Titan’s horizon. The signals, relayed by
Cassini, were picked up by NASA’s Deep Space Network and delivered
immediately to ESOC. The first science data arrived at 16:19 GMT.
Huygens
was humankind’s first attempt to land a probe on another world in the
outer Solar System. “This is a great achievement for Europe and its US
partners in this ambitious international endeavour to explore Saturn
system,” said Jean-Jacques Dordain, then ESA’s Director General.
This image is a stereographic (fish-eye) projection taken with the descent imager/spectral radiometer on Huygens.
Source: ESA/Space Images
