WEB FOCUS
Huygens on Titan
In this focus:
Sponsor | Current research | Hygens Descent Animation | Hygens Descent Audio | Links | Archive
Saturn's moon Titan — larger than the planet Mercury and with an atmosphere — has always intrigued astronomers. Results exceeded expectations when the Huygens probe deployed its parachutes and drifted down through Titan's chemical haze, revealing bright highlands that drain in a river-like way to flat, dark lowlands, before landing in a material with the consistency of wet sand after a descent of 2 hr 28 min. The first results were published in the 8 December 2005 issue of Nature and this special web focus presents the latest findings alongside a comprehensive archive of papers about this fascinating moon. The sights and sounds of Huygens' incredible journey are also featured in multimedia files including a brilliant descent animation. Supported by ESA. Nature carries sole responsibility for all editorial content. Image: ESA
Current research
NEWS AND VIEWS
Planetary science: Huygens rediscovers Titan Free access
Tobias Owen
Nature 438, 756 (08 December 2005) doi:10.1038/438756a
ARTICLE
In situ measurements of the physical characteristics of Titan's environment Free access
M. Fulchignoni et al.
Nature 438, 785–791 (08 December 2005) doi:10.1038/nature04314
An overview of the descent and landing of the Huygens probe on Titan Free access
Jean-Pierre Lebreton
Nature 438, 758–764 (08 December 2005) doi:10.1038/nature04347
Abstract | Full Text | PDF | Supplementary Information
The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe Free access
H. B. Niemann et al.
Nature 438, 779–784 (08 December 2005) doi:10.1038/nature04122
Rain, winds and haze during the Huygens probe's descent to Titan's surface Free access
M. G. Tomasko
Nature 438, 765–778 (08 December 2005) doi:10.1038/nature04126
A soft solid surface on Titan as revealed by the Huygens Surface Science Package Free access
John C. Zarnecki et al.
Nature 438, 792–795 (08 December 2005) doi:10.1038/nature04211
LETTER
The vertical profile of winds on Titan Free access
M. K. Bird et al.
Nature 438, 800–802 (08 December 2005) doi:10.1038/nature04126
Abstract | Full Text | PDF | Supplementary Information
Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis Free access
G. Israël et al.
Nature 438, 796–799 (08 December 2005) doi:10.1038/nature04349
Abstract | Full Text | PDF | Supplementary Information
NEWS
Titan: tapping the flood of data Free access
As the first analyses of the Huygens mission to Titan are published, Mark Peplow charts the satellite's transition from fogbound moon to familiar landscape, and finds out why scientists long to return.
Nature 438, 538–539 (01 December 2005) doi:10.1038/438538a
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Huygens Descent Animation
Touchdown on Titan! Lasting about 1 minute, this descent animation (16.1MB) starts at an altitude of 300 km and follows the eastward trajectory that the Huygens probe travelled along during its journey to Titan's surface. A higher resolution file (35MB) is also available.
Cassini orbiter ISS (Imaging Science Subsystem), RADAR & VIMS (Visual and Infrared Mapping Spectrometer) images are displayed in quick succession followed by DISR (Huygens Descent Imager/Spectral Radiometer) mosaics from increasingly lower altitudes. The longitude/latitude grid lines are separated by 2 degrees.
The surface colour is approximately what a human observer riding along with the probe would see if she or he could see through Titan's atmospheric haze. In the last few kilometres the point-of-view turns south, the direction the Huygens Probe is believed to be facing as it sits on the surface today, and the approximate landing site is marked with a dotted-circle.
The DISR images are relatively unique in the change of scale they display as Titan transforms from a planetary mass to an alien landscape. Three cameras, whose combined field of view was a narrow vertical slice stretching from nadir to horizon, recorded images as fast as they could be transmitted to the Cassini Orbiter. They were projected from above to preserve scale and then projected with a perspective that mimicked what an observer riding the probe would see. Each second of the animation encompasses 30 frames. Credit: ESA/NASA/ASI. Animated by Bashar Rizk, Lunar & Planetary laboratory, University of Arizona.
Top of pageHuygens Descent Audio
Speeding through Titan's haze
The Huygens Atmospheric Structure Instrument (HASI) onboard the Huygens probe is a multisensor package designed to measure the physical quantities characterizing Titan's atmosphere. During the Huygens' descent (HASI) recorded the average "sound spectrum" (though it is not the same as recorded sound - the acoustic sensor is a pressure transducer). However, data revealed by these 'sounds' might include the rush of the atmosphere, wind, thunder from local storms, the deployment of the probe's braking parachutes, and perhaps the splash of liquid methane rain.
This recording is a laboratory reconstruction of the sounds heard by Huygens' microphones. Several sound samples, taken at different times during the descent, are combined and give a realistic reproduction of what a traveller onboard Huygens would have heard during one minute of the descent through Titan's atmosphere. Credit: ESA/ASI/UPD/IWF.
Radar echoes from Titan's surface
This recording was produced by converting into audible sounds some of the radar echoes received by Huygens during the last few kilometres of its descent onto Titan. As the probe approaches the ground, both the pitch and intensity increase. Aspects of Titan's surface topography can be inferred from the intensity and pattern of the echoes. Credit: ESA/ASI/UPD/CNRS/IAA/RSSD/IWF.
Web links
- News@nature.com Destination: Titan special
- News@nature.com Cassini special
- NASA Cassini-Huygens page
- ESA Cassini-Huygens page
- The Planetary Society - Cassini-Huygens page
- Nineplanets.org - Titan
- DISR instrument team, University of Arizona
- Huygens Atmospheric Structure Instrument (HASI) page
Archive
It has now been over six decades since the discovery of Titan's thick atmosphere (although such a possibility was hinted at as early as 1907), during which time this unusual moon has been a continuous source of academic fascination and speculation. Here we bring together a collection of papers on Titan from Nature's archive, illustrating how our views on atmospheric composition, surface properties and - most notably - the tantalizing possibility of liquid oceans have evolved over time.
LETTERS TO EDITOR
No oceans on Titan from the absence of a near-infrared specular reflection Free access
R. A. West et al.
Nature 436, 670–672 (04 August 2005) doi:10.1038/nature03824
NEWS AND VIEWS
Planetary science: Shades of Titan
Louise Prockter
Nature 435, 749–750 (09 June 2005) doi:10.1038/435749a
LETTERS TO EDITOR
Release of volatiles from a possible cryovolcano from near-infrared imaging of Titan
C. Sotin et al.
Nature 435, 786–789 (09 June 2005) doi:10.1038/nature03596
ARTICLE
Imaging of Titan from the Cassini spacecraft
Carolyn C. Porco et al.
Nature 434, 159–168 (10 March 2005) doi:10.1038/nature03436
LETTERS
Direct detection of variable tropospheric clouds near Titan's south pole Free access
Michael E. Brown et al.
Nature 420, 795–797 (19 December 2002) doi:10.1038/nature01302
A wind origin for Titan's haze structure
P. Rannou et al.
Nature 418, 853–856 (22 August 2002) doi:10.1038/nature00961
Stable methane hydrate above 2 GPa and the source of Titan's atmospheric methane
J. S. Loveday et al.
Nature 410, 661–663 (05 April 2001) doi:10.1038/35070513
NEWS AND VIEWS
Planetary science: Titan weather report
F. Michael Flasar
Nature 395, 541–543 (08 October 1998) doi:10.1038/26847
LETTERS
Transient clouds in Titan's lower atmosphere
Caitlin A. Griffith, Tobias Owen, Gary A Miller, Thomas Geballe
Nature 395, 575–578 (08 October 1998) doi:10.1038/26920
Tidal effects of disconnected hydrocarbon seas on Titan
Stanley F. Dermott, Carl Sagan
Nature 374, 238-240 (16 March 1995) doi:10.1038/374238a0
Evidence for surface heterogeneity on Titan
Caitlin A. Griffith
Nature 364, 511-514 (05 August 1993) doi:10.1038/364511a0
Meteoroid ablation processes in Titan's atmosphere
W-H. Ip
Nature 345, 511-512 (07 June 1990) doi:10.1038/345511a0
Upper limit set for level of lightning activity on Titan
M. D. Desch, M. L. Kaiser
Nature 343, 442-444 (01 February 1990) doi:10.1038/343442a0
NEWS AND VIEWS
An occult view of Titan
James Elliot
Nature 343, 315-316 (25 January 1990) doi:10.1038/343315a0
LETTERS TO EDITOR
Probing Titan's atmosphere by stellar occultation
B. Sicardy et al.
Nature 343, 350-353 (25 January 1990) doi:10.1038/343350a0
Results for Titan's atmosphere from its occultation of 28 Sagittarii
W. B. Hubbard et al.
Nature 343, 353-355 (25 January 1990) doi:10.1038/343353a0
High-temperature shock formation of N2 and organics on primordial Titan
Christopher P. McKay et al.
Nature 322, 520-522 (07 April 1988) doi:10.1038/332520a0
D to H ratio and the origin and evolution of Titan's atmosphere
Joseph P. Pinto, Jonathan I. Lunine, Sang-Joon Kim, Yuk L. Yung
Nature 319, 388-390 (30 January 1986) doi:10.1038/319388a0
Organic synthesis in the atmosphere of Titan Free access
S. Gupta, E. Ochiai, C. Ponnamperuma
Nature 293, 725-727 (29 October 1981) doi:10.1038/293725a0
Formation of organic molecules on Titan
Louis A. Capone et al.
Nature 293, 45-46 (03 Sep 1981) doi:10.1038/293045a0
NEWS AND VIEWS
Titan's atmosphere: temperature and dynamics
F. M. Flasar, R. E. Samuelson, B. J. Conrath
Nature 292, 693-698 (20 August 1981 doi:10.1038/292683a0
C3H8 and C3H4 in Titan's atmosphere
W. C. Maguire, R. A. Hanel, D. E. Jennings, V. G. Kunde, R. E. Samuelson
Nature 292, 683-686 (20 August 1981) doi:10.1038/292683a0
Implications of Titan's north-south brightness asymmetry Free access
Nature 292, 698-702 (20 August 1981) doi:10.1038/292698a
C4H2, HC3N and C2N2 in Titan's atmosphere
V. G. Kunde et al.
Nature 292, 686-688 (20 August 1981) doi:10.1038/292686a0
Mean molecular weight and hydrogen abundance of Titan's atmosphere
R. E. Samuelson et al.
Nature 292, 688-693 (20 Aug 1981) doi:10.1038/292688a0
LETTERS TO EDITOR
Effect of Noble Gases on an Atmospheric Greenhouse (Titan)
Robert Cess and Tobias Owen
Nature 244, 272-273 (03 August 1973) doi:10.1038/244272a0