This is a classic article from 快猫短视频鈥檚 archive, republished as part of our 50th anniversary celebrations
A MACHINE from Earth is now resting on an ice-strewn plain a billion kilometres away. The Huygens probe landed on Titan last Friday. It started transmitting during its descent and kept on going far longer than anyone expected after it reached the surface. The images and other data it sent back are extraordinary. Although analysis has barely begun, educated guesses by the Huygens team are giving us a first impression of this new world.
After the failure of the European Space Agency鈥檚 Beagle 2 trip to Mars in 2003, mission scientists were understandably tense as Huygens approached Titan. So when radio telescopes on Earth reported that Huygens was transmitting successfully, there was a huge release of tension. 鈥淚鈥檝e seen people with tears in their eyes,鈥� said ESA scientist Mike McKay.
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One startling image shows a network of sinuous lines crossing a bright region, and a sharp boundary between that area and a featureless dark expanse. 鈥淚t seems to me we are seeing evidence of drainage channels, and perhaps a shoreline,鈥� says Marty Tomasko of the University of Arizona, who heads the Huygens imaging and spectroscopy team.
The channels are shorter and stubbier than river valleys on Earth, possibly carved by fluid oozing out of their sides. As the surface temperature is a chilly 94 kelvin (-179 掳C), this fluid is probably liquid ethane, methane or some other hydrocarbon. The channels appear to drain into the dark regions of Titan. 鈥淭he darker areas seem very flat,鈥� says Tomasko. 鈥淧robably the dark areas are evidence of flooding.鈥�
Huygens鈥檚 cameras looked out on a plain covered in rounded, fist-sized lumps of ice. Like a human explorer, the probe gathered its impressions of Titan through a range of senses. Even as it landed it tested the texture of the ground using a metal rod poking out of the bottom of the craft, attached to a device to measure the force of impact. 鈥淭he closest analogue in consistency is wet sand or clay,鈥� said John Zarnecki of the Open University in Milton Keynes, UK, leader of the surface science team. Another member of the team compared the ground to cr猫me br没l茅e.
The probe鈥檚 cameras also recorded the spectrum of light reflected from the surface, which will be compared with spectra from a host of complex organic materials to look for a match. And Huygens鈥檚 chemical analyser appears to have sniffed out some of the surface chemicals. Its inlet was heated up to vaporise some ground material. The instrument detected a puff of methane just after impact.
This article was originally published in 快猫短视频 on 22 January 2005
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