Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

First ’in situ’ composition measurements made in Titan’s atmosphere

01.12.2005


Unique results from the Aerosol Collector and Pyrolyser (ACP) and the Gas Chromatograph Mass Spectrometer (GCMS) have given scientists their first in situ chemical data on Titan’s atmosphere, including aerosols, chemical composition and isotopes.



Two of Titan’s key unknowns are the origin of the molecular nitrogen and methane in the atmosphere, and the mechanisms by which methane is maintained in the face of rapid destruction by photochemistry (chemical processes that are accompanied by or catalysed by the emission or absorption of visible or ultraviolet light).

The GCMS measured chemical composition and isotope abundances from 140 km altitude to the surface and confirmed the primary constituents were nitrogen and methane, and that the haze in the atmosphere is primarily methane.


From isotopic ratio measurements, the Huygens scientists obtained two key findings. The carbon isotope ratio (12C/13C) measured in methane suggests a continuous or periodic replenishment of methane in the atmosphere, but no evidence was found of active biological systems.

The nitrogen isotope ratio (14N/15N) suggests to the scientists that the early atmosphere of Titan was five times denser than it is now, and hence lost nitrogen to space.

Argon 36 was detected for the first time, but not xenon or krypton. However, the argon was found in low abundance, which is especially interesting because of the huge, nitrogen-dominated atmosphere and because about 50% of the mass of Titan is water ice, known to be a potentially efficient carrier of noble gases.

This low abundance implies the atmosphere was condensed or captured as ammonia, instead of nitrogen. The non-detection of the other noble gases, a surprising finding, will also fuel theories of the origin and evolution of Titan’s atmosphere.

The composition of surface vapours obtained by GCMS after landing shows that Huygens landed on a surface wet with methane, which evaporated as the cold soil was heated by the warmer probe. The surface was also rich in organic compounds not seen in the atmosphere, for example cyanogen and ethane, indicating a complex chemistry on Titan’s surface as well as in the atmosphere.

Argon 40 was also detected at the surface and its presence indicates that Titan has experienced in the past, and is most likely still experiencing today, internal geological activity.

Titan’s aerosols play an important role in determining atmospheric thermal structure, affecting the processes of radiative heating and cooling. They can help to create warm and cold layers that in turn contribute to circulation patterns and determine the strengths of winds.

The ACP obtained direct measurements of the chemical make-up of these aerosol particles. From an analysis of the products obtained by pyrolysis (chemical decomposition of organic materials by heating) of aerosols at 600°C, ammonia and hydrogen cyanide were the first molecules identified.

This is of prime importance because ammonia is not present as a gas in the atmosphere, hence the aerosols must include the results of chemical reactions that may have produced complex organic molecules. They are not simply condensates.

Aerosol particles may also act as condensation nuclei for cloud formation, and are the end-products of a complex organic chemistry which is important in astrobiology. Indeed, Titan offers the possibility to observe chemical pathways involving molecules that may have been the building blocks of life on Earth.

Franco Bonacina | alfa
Further information:
http://www.esa.int/SPECIALS/Results_from_Mars_Express_and_Huygens/SEMK1TULWFE_0.html

More articles from Earth Sciences:

nachricht Multi-year submarine-canyon study challenges textbook theories about turbidity currents
12.12.2017 | Monterey Bay Aquarium Research Institute

nachricht How do megacities impact coastal seas? Searching for evidence in Chinese marginal seas
11.12.2017 | Leibniz-Institut für Ostseeforschung Warnemünde

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>