Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Huygens Articles
  • Published:

An overview of the descent and landing of the Huygens probe on Titan

Abstract

Titan, Saturn's largest moon, is the only Solar System planetary body other than Earth with a thick nitrogen atmosphere. The Voyager spacecraft confirmed that methane was the second-most abundant atmospheric constituent in Titan's atmosphere, and revealed a rich organic chemistry, but its cameras could not see through the thick organic haze. After a seven-year interplanetary journey on board the Cassini orbiter, the Huygens probe was released on 25 December 2004. It reached the upper layer of Titan's atmosphere on 14 January and landed softly after a parachute descent of almost 2.5 hours. Here we report an overview of the Huygens mission, which enabled studies of the atmosphere and surface, including in situ sampling of the organic chemistry, and revealed an Earth-like landscape. The probe descended over the boundary between a bright icy terrain eroded by fluvial activity—probably due to methane—and a darker area that looked like a river- or lake-bed. Post-landing images showed centimetre-sized surface details.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Accommodation of the payload seen from two different perspectives.
Figure 2: Orbiter trajectory during the probe mission.
Figure 3: Probe targeting as seen on a projection of the Titan disk.
Figure 4: Spin rate profile as a function of time.
Figure 5: Reconstructed altitude and descent speed as a function of mission time.

Similar content being viewed by others

References

  1. Smith, P. H. et al. Titan's surface revealed by HST imaging. Icarus 119, 336–349 (1996)

    Article  ADS  Google Scholar 

  2. Meier, R., Smith, B. A., Owen, T. C. & Terrile, R. J. The surface of Titan from NICMOS observations with the Hubble Space Telescope. Icarus 145, 462–473 (2000)

    Article  ADS  Google Scholar 

  3. Gibbard, S. G. et al. Titan: high-resolution speckle images from the Keck telescope. Icarus 139, 189–201 (1999)

    Article  ADS  CAS  Google Scholar 

  4. Coustenis, A. et al. Maps of Titan's surface from 1 to 2.5 µm. Icarus 177, 89–105 (2005)

    Article  ADS  Google Scholar 

  5. Porco, C. C. et al. Imaging of Titan from the Cassini spacecraft. Nature 434, 156–165 (2005)

    Article  ADS  Google Scholar 

  6. Campbell, D. B., Black, G. J., Carter, L. M. & Ostro, S. J. Radar evidence for liquid surfaces on Titan. Science 302, 431–434 (2003)

    Article  ADS  CAS  Google Scholar 

  7. Lebreton, J.-P. & Matson, D. L. The Huygens probe: science, payload and mission overview. Space Sci. Rev. 104, 59–100 (2002)

    Article  ADS  Google Scholar 

  8. Matson, D. L., Spilker, L. J. & Lebreton, J.-P. The Cassini-Huygens mission to the saturnian system. Space Sci. Rev. 104, 1–58 (2002)

    Article  ADS  Google Scholar 

  9. Fulchignoni, M. et al. The characterisation of Titan's atmospheric physical properties by the Huygens Atmospheric Structure Instrument (HASI). Space Sci. Rev. 104, 395–431 (2002)

    Article  ADS  Google Scholar 

  10. Bird, M. K. et al. The Huygens Doppler Wind Experiment—Titan winds derived from probe radio frequency measurements. Space Sci. Rev. 104, 613–640 (2002)

    Article  ADS  Google Scholar 

  11. Israel, G. et al. Huygens probe aerosol collector pyrolyser. Space Sci. Rev. 104, 433–468 (2002)

    Article  ADS  CAS  Google Scholar 

  12. Niemann, H. B. et al. The gas chromatograph mass spectrometer for the Huygens probe. Space Sci. Rev. 104, 553–591 (2002)

    Article  ADS  CAS  Google Scholar 

  13. Zarnecki, J. C. et al. Huygens' surface science package. Space Sci. Rev. 104, 593–611 (2002)

    Article  ADS  Google Scholar 

  14. Tomasko, M. G. et al. The Descent Imager/Spectral Radiometer (DISR) experiment on the Huygens entry probe of Titan. Space Sci. Rev. 104, 469–551 (2002)

    Article  ADS  Google Scholar 

  15. Fulchignoni, M. et al. In situ measurements of the physical characteristics of Titan's environment. Nature doi:10.1038/nature04314 (this issue)

  16. Clausen, K. C. et al. The Huygens probe system design. Space Sci. Rev. 104, 155–189 (2002)

    Article  ADS  Google Scholar 

  17. Pogrebenko, S., et al. in Proceedings of the International Workshop: Planetary Probe Atmospheric Entry and Descent Trajectory Analysis and Science (6–9 October 2003, Lisbon) (ed. Wilson, A.) 197–204 (ESA SP-544, ESA Publications Division, Noordwijk, 2004)

    Google Scholar 

  18. Bird, M. K. et al. The vertical profile of winds on Titan. Nature doi:10.1038/nature04060 (this issue)

  19. Tomasko, M. G. et al. Rain, winds and haze during the Huygens probe's descent to Titan's surface. Nature doi:10.1038/nature04126 (this issue)

  20. Zarnecki, J. C. et al. A soft solid surface on Titan as revealed by the Huygens Surface Science Package. Nature doi:10.1038/nature04211 (this issue)

  21. Niemann, H. B. et al. The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe. Nature doi:10.1038/nature04122 (this issue)

  22. Israël, G. et al. Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis. Nature doi:10.1038/nature04349 (this issue)

  23. Waite, H. et al. Ion neutral mass spectrometer results from the first flyby of Titan. Science 308, 982–986 (2005)

    Article  ADS  CAS  Google Scholar 

  24. Atkinson, D. H., Kazeminejad, B., Gaborit, V., Ferri, F. & Lebreton, J.-P. Huygens probe entry and descent trajectory analysis and reconstruction techniques. Planet. Space Sci. 53, 586–593 (2005)

    Article  ADS  Google Scholar 

  25. Kazeminejad, B. Methodology Development for the Reconstruction of the ESA Huygens Probe Entry and Descent Trajectory. PhD thesis, Karl-Franzens Univ. (2005)

    Google Scholar 

  26. Kazeminejad, B. & Atkinson, D. H. The ESA Huygens probe entry and descent trajectory reconstruction. In Proceedings of the International Workshop: Planetary Probe Atmospheric Entry and Descent Trajectory Analysis and Science (6–9 October 2003, Lisbon) (ed. Wilson, A.) 137–149 (ESA SP-544, ESA Publications Division, Noordwijk, 2004)

    Google Scholar 

  27. Kazeminejad, B. et al. Simulation and analysis of the revised Huygens Probe entry and descent trajectory and radio link model. Planet. Space Sci. 52, 799–814 (2004)

    Article  ADS  Google Scholar 

  28. Lorenz, R. D. & Mitton, J. Lifting Titan's Veil (Cambridge Univ. Press, Cambridge, UK, 2002)

    Google Scholar 

  29. Raulin, F. & Owen, T. Organic chemistry and exobiology on Titan. Space Sci. Rev. 104, 377–394 (2002)

    Article  ADS  CAS  Google Scholar 

  30. Schulze-Makuch, D. & Grinspoon, D. H. Biologically enhanced energy and carbon cycling on Titan. Astrobiology 5(4), 560–567 (2005)

    Article  ADS  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

The Cassini-Huygens mission is the result of an exemplary international collaboration in space exploration. Huygens involved more than 40 European industries and two US suppliers. The work of the members of the Cassini and Huygens teams from ESA, NASA/JPL, the Huygens industrial consortium led by Alcatel, and all Cassini-Huygens investigators is acknowledged. We especially acknowledge the Cassini orbiter teams that made their early observations available in advance to Huygens, and to R. Yelle for his leadership in coordinating the Titan Atmosphere Model Working Group. Special acknowledgements to B. Smeds for his work in designing and managing the Huygens link test that allowed the Doppler problem to be detected and solved, to L. Popken for his modelling of the Huygens Digital Radio Receiver and to the whole Huygens recovery task force led by K. Clausen and L. Deutsch. We thank K. van't Klooster for his efforts to initiate and promote the Huygens VLBI experiment, and J. Louet for his support. The Earth-Based Huygens Doppler tracking experiment is led by W. Folkner. We appreciated the support provided by the National Radio Astronomy Observatory (NRAO), operated by Associated Universities Inc., under a cooperative agreement with the NSF, and the one provided by the Australia Telescope National Facility (ATNF) managed by CSIRO. We also thank M. Bird, R. Lorenz, R. A. Preston and J. C. Zarnecki for a careful reading of various versions of the manuscript and for providing comments.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Jean-Pierre Lebreton.

Ethics declarations

Competing interests

Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.

Supplementary information

Supplementary Figure 1

This figure shows an exploded view of the Huygens probe. (PDF 47 kb)

Supplementary Figure 2

This figure shows the accelerometer measurements (engineering sensors) during the whole descent. (PDF 79 kb)

Supplementary Figure 3

This figure shows the evolution of the probe internal temperature measurement during the descent and on the surface. (PDF 60 kb)

Supplementary Figure 4

This figure illustrates the overall variation of the communication radio link parameter during the mission and provides a comparison between the predicted signal envelope and the measured signal strength, both during the descent (probe spinning) and on the ground. (PDF 65 kb)

Supplementary Figure 5

This figure shows the location of all the radio telescopes that were used to receive the Huygens carrier signal. The telescope configuration is shown as seen from Titan at the beginning (left panel) and at the end (right panel) of the observation. (PDF 48 kb)

Supplementary Figure 6

This figure shows the path of the direct signal transmitted by Huygens and of the one reflected by the ground. The two signals produces an interference pattern that was detected on board Cassini. (PDF 47 kb)

Supplementary Notes

This includes Supplementary Table 1 (details about the six Huygens investigations), Supplementary Table 2 (a list of 17 radio telescopes that were part of the Huygens radio astronomy segment of the mission), Supplementary Figure Legends and technical information about the probe that was not appropriate to include in the printed version. It also describes the technical details of the radio astronomy segment of the Huygens mission. (DOC 65 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Lebreton, JP., Witasse, O., Sollazzo, C. et al. An overview of the descent and landing of the Huygens probe on Titan. Nature 438, 758–764 (2005). https://doi.org/10.1038/nature04347

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature04347

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing