Titan’s atmosphere even more Earth-like than previously thought

Posted: July 31, 2015 by oldbrew in research, solar system dynamics
Tags: ,

Saturn's moon Titan [image credit: NASA - Cassini]

Saturn’s moon Titan
[image credit: NASA – Cassini]


Clues here in Earth-like atmospheric behaviours of planetary bodies, as reported by Saturn Daily. This despite the fact that Titan orbits Saturn rather than the Sun.

Scientists at UCL have observed how a widespread polar wind is driving gas from the atmosphere of Saturn’s moon Titan. The team analysed data gathered over seven years by the international Cassini probe, and found that the interactions between Titan’s atmosphere, and the solar magnetic field and radiation, create a wind of hydrocarbons and nitriles being blown away from its polar regions into space. This is very similar to the wind observed coming from the Earth’s polar regions. [bold added]


Titan is a remarkable object in the Solar System. Like Earth and Venus, and unlike any other moon, it has a rocky surface and a thick atmosphere. It is the only object in the Solar System aside from the Earth to have rivers, rainfall and seas. It is bigger than the planet Mercury.

Thanks to these unique features, Titan has been studied more than any moon other than Earth’s, including numerous fly-bys by the Cassini probe, as well as the Huygens lander which touched down in 2004. On board Cassini is an instrument partly designed at UCL, the Cassini Plasma Spectrometer (CAPS), which was used in this study.

“Titan’s atmosphere is made up mainly of nitrogen and methane, with 50% higher pressure at its surface than on Earth,” said Andrew Coates (UCL Mullard Space Science Laboratory), who led the study. “Data from CAPS proved a few years ago that the top of Titan’s atmosphere is losing about seven tonnes of hydrocarbons and nitriles every day, but didn’t explain why this was happening. Our new study provides evidence for why this is happening.”

Hydrocarbons are a category of molecules that includes methane, as well as other familiar substances including petrol, natural gas and bitumen. Nitriles are molecules with nitrogen and carbon tightly bound together.

The new research, published in the journal Geophysical Research Letters, explains that this atmospheric loss is driven by a polar wind powered by an interaction between sunlight, the solar magnetic field and the molecules present in the upper atmosphere.

Full report: Titan’s atmosphere even more Earth-like than previously thought.

Copyrighted image of Titan’s atmosphere here: http://apod.nasa.gov/apod/ap110401.html

HUYGENS PROBE DESCENDING THROUGH TITAN’S ATMOSPHERE (credit: ESA)

Comments
  1. oldbrew says:

    See also: ‘Robinson and Catling model closely matches data for Titan’s atmosphere’
    https://tallbloke.wordpress.com/2014/06/29/robinson-and-catling-model-closely-matches-data-for-titans-atmosphere/

    Re. hydrocarbons on a ‘non-fossil’ planetary body: ‘Fossil fuels puzzle’
    https://tallbloke.wordpress.com/2014/04/12/fossil-fuels-puzzle/

  2. tchannon says:

    Loss is normal, Venus, Earth, Jupiter, Saturn.

    7 tonnes a day? Is that all ? Time to look at decimal points.

    Allied to this topic is a day old item I considered turning into an article.

    A new claim the Earth had a magnetic field earlier than previously claimed. This is critical to atmosphere stripping. I suspect it if true also alters assumptions make to do with the faint sun paradox.

    Here we are oldbrew
    http://www.rochester.edu/newscenter/researchers-find-that-earths-magnetic-shield-is-500-million-years-older-than-previously-thought-112772/

  3. oldbrew says:

    tc: Link …”A strong magnetic field provides a shield for the atmosphere,” said Tarduno…
    and ‘the Red Planet had no magnetic field to protect the atmosphere, which may explain why its atmosphere is so thin.’

    Venus has almost no magnetic field, but by far the thickest atmosphere of the inner planets.
    It’s also closer to the Sun so the solar wind effect is more powerful than at Earth.

    Theory?

  4. tchannon says:

    Quite so, settled science.🙂

    I have a vague recollection reading the effect is related to atomic mass, free hydrogen is lost most easily.

    A leap, probably wrong, add hydrogen to Venus atmosphere and you get H2O and various HC compounds as opposed to combined C and O, might be a water world with coal and oil.

  5. oldbrew says:

    2011: ‘How Vital Is a Planet’s Magnetic Field? New Debate Rises’

    “My opinion is that the magnetic shield hypothesis is unproven,” said Robert Strangeway from UCLA. “There’s nothing in the contemporary data to warrant invoking magnetic fields.”
    http://www.space.com/11187-earth-magnetic-field-solar-wind.html

  6. tchannon says:

    So he doesn’t have data on hydrogen.

    Closer to the sun Venus has elevated reactivity and a more intense solar wind. Really though holding to a radically different opinion from that held by peers is career threatening.

  7. vukcevic says:

    Hi all
    Titan is interesting, but what about two steps closer to home.
    Can anyone explain how the structure shown in the top image here:
    http://www.vukcevic.talktalk.net/S2.htm
    came about naturally (wind or precipitation erosion, earthquakes, volcanism, meteorite impact, succession of high and low temperatures, or any other natural process) .
    And what about the second, is that a 140km long meteorite trail? Could it be a case for “houston, we have a problem”.

  8. oldbrew says:

    There are theories that Venus has ‘an induced magnetosphere’ but they seem a bit strained for my taste, i.e trying to push the magnetosphere argument when the absence of one on Venus seems already to have killed it.

  9. “Titan’s atmosphere, and the solar magnetic field and radiation, create a wind of hydrocarbons and nitriles being blown away from its polar regions into space. This is very similar to the wind observed coming from the Earth’s polar regions. [bold added]”

    Huh! This is exactly the opposite of what is observed At the Earth’s poles. Here the lower temperature and lower energy density atmosphere at the poles strictly reduces pressure/altitude. At the Earth’s poles almost no mass is “blown away from its polar regions into space”. The Earth’s polar wind is strictly in the direction of the equator in all seasons.🙂

  10. Paul Vaughan says:

    Paradigm Shifts
    “Do planets exist outside our solar system?”
    “Does water exist beyond Earth?”
    Such questions used to meet ridicule.
    …and then the ridicule vanished.

  11. tchannon says: July 31, 2015 at 5:04 pm

    Quite so, settled science.🙂

    “I have a vague recollection reading the effect is related to atomic mass, free hydrogen is lost most easily.”

    “A leap, probably wrong, add hydrogen to Venus atmosphere and you get H2O and various HC compounds as opposed to combined C and O, might be a water world with coal and oil.”

    Only for those that believe they can futz with “what hath GOD wrought”. hubris, arrogance, conceit, haughtiness, hauteur, pride, self-importance, egotism, pomposity, superciliousness, superiority. Take your pick!!🙂

  12. Kristian says:

    Will Janoschka says, July 31, 2015 at 11:28 pm:

    “Huh! This is exactly the opposite of what is observed At the Earth’s poles. Here the lower temperature and lower energy density atmosphere at the poles strictly reduces pressure/altitude. At the Earth’s poles almost no mass is “blown away from its polar regions into space”. The Earth’s polar wind is strictly in the direction of the equator in all seasons. :-)”

    Will, I think they are referring to atmospheric layers above the troposphere. The hydrocarbons in Titan’s atmosphere are mostly to be found in the stratosphere and up.

  13. Kristian says: August 1, 2015 at 12:17 am
    Will Janoschka says, July 31, 2015 at 11:28 pm:

    (“Huh! This is exactly the opposite of what is observed At the Earth’s poles. Here the lower temperature and lower energy density atmosphere at the poles strictly reduces pressure/altitude. At the Earth’s poles almost no mass is “blown away from its polar regions into space”. The Earth’s polar wind is strictly in the direction of the equator in all seasons.🙂 ”)

    “Will, I think they are referring to atmospheric layers above the troposphere. The hydrocarbons in Titan’s atmosphere are mostly to be found in the stratosphere and up.”

    OK Kristian,
    Thank you. I have not been to Titan to do any measurement. I believe not a word from the ClimAstrologists!…. All the best. -will-

  14. J Martin says:

    Vuk. Maybe the next NASA lander can go take a look.

  15. vukcevic says:

    Hi JM
    I hope so, but I doubt it. I’ve looked mainly at the Equatorial (warmest) area, usually noting exceptional, lot of volcanic or meteorite craters, alluvial features, etc. However, in this area none of the above, just those two features, almost parallel but very different, I can not see a convincing explanation for either of two.

  16. oldbrew says:

    Climate of Titan – From Wikipedia says (two quotes):
    ‘The climate of Titan, the largest moon of Saturn, is similar in many respects to that of Earth, despite having a far lower surface temperature.’

    ‘Titan receives just about 1% of the amount of sunlight Earth gets. The average surface temperature is about 94 K (−179 °C, or −290 °F).’
    http://en.wikipedia.org/wiki/Climate_of_Titan
    (NB ignore Wikipedia nonsense calcs. re greenhouses)

    The Sun follows this rule:
    ‘The rate of radiation heat loss is proportional to the emittance of the surface and the difference in temperature to the fourth power.’
    http://www.powerfromthesun.net/Book/chapter05/chapter05.html

    Titan is the same distance from the Sun as Saturn, therefore its solar irradiance relative to Earth is around 0.011 – see Solar irradiance (W/m2) – Ratio (Saturn/Earth) here:
    http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html

    The fourth root of 0.011 is 0.323.
    Earth’s average temperature is about 288 degrees Kelvin (273 Kelvin = 0 deg. Centigrade).
    288 x 0.323 = 93.024 Kelvin.

    This corresponds very well with the temperature quoted above by Wikipedia: ‘about 94K’.
    No convoluted Wikipedia-type greenhouse gas calculations necessary🙂

  17. oldbrew says:

    NASA says: ‘This graphic illustrates the differences in Titan’s and Earth’s atmospheres. Titan’s atmosphere extends 10 times further into space than Earth’s.’