Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Titan’s turbulence surprises scientists

01.12.2005


Strong turbulence in the upper atmosphere, a second ionospheric layer and possible lightning were among the surprises found by the Huygens Atmospheric Structure Instrument (HASI) during the descent to Titan’s surface.



HASI provided measurements from an altitude of 1400 km down to the surface of the physical characteristics of the atmosphere and surface, such as temperature and density profiles, electrical conductivity, and surface structure. The Huygens SSP made measurements just above and on the surface of Titan.

High-altitude atmospheric structure had been inferred from earlier solar occultation measurements by Voyager, but the middle atmosphere (200–600 km) was not well determined, although telescopic observations indicated a complex vertical structure.


Very little was known about the surface of Titan because it is hidden by a thick ’haze’ - initial speculation was that the surface was covered by a deep hydrocarbon ocean, but infrared and radar measurements showed definite albedo contrasts —possibly consistent with lakes, but not with a global ocean.

Earlier observations showed that the surface pressure on Titan was comparable to that on Earth, and that methane formed a plausible counterpart to terrestrial water for cloud and rain formation. There was also speculation on the possibility of lightning occurring in Titan’s atmosphere that could affect the chemical composition of the atmosphere.

HASI found that in the upper part of the atmosphere, the temperature and density were both higher than expected. The temperature structure shows strong wave-like variations of 10-20 K about a mean of about 170 K. This, together with other evidence, indicates that Titan’s atmosphere has many different layers.

Models of Titan’s ionosphere predicted that galactic cosmic rays would produce an ionospheric layer with a maximum concentration of electrons between 70 and 90 km altitude. HASI also surprised the Huygens team by finding a second lower ionospheric layer, between 140 km and 40 km, with electrical conductivity peaking near 60 km.

HASI may also have seen the signature of lightning. Several electrical field impulse events were observed during the descent, caused by possible lightning activity in the spherical waveguide formed by the surface of Titan and the inner boundary of its ionosphere.

The vertical resolution of the temperature measurement was sufficient to resolve the structure of the planetary boundary layer. This boundary layer had a thickness of about 300 m at the place and time of landing. The surface temperature was accurately measured at 93.65±0.25 K and the pressure 1467±1 hPa (very close to measurements made earlier by Voyager, about 95K and 1400 hPa).

Franco Bonacina | alfa
Further information:
http://www.esa.int/SPECIALS/Results_from_Mars_Express_and_Huygens/SEMLKRULWFE_0.html

More articles from Physics and Astronomy:

nachricht Witnessing turbulent motion in the atmosphere of a distant star
23.08.2017 | Max-Planck-Institut für Radioastronomie

nachricht Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>