Mysterious TITAN

Larger than the planets Mercury or Pluto, Titan is the third largest moon in our solar system with a radius of 2,575 kilometers, which lies at a mean distance of 1,221,850 km from its parent the ringed planet Saturn. This is a rather peculiar moon that has a dense fogy atmosphere hiding its surface. Titan takes 15 days 22 hours 41 minutes to orbit Saturn, and we know that its average density is 1.88 grams per cubic centimeter.

The Voyager space probes visited Saturn in the mid 1980s and made many observations of Titan. Many of the images returned only show Titan's yellow-orange cloud tops, and little in the way of atmospheric features. However, Voyager-I did observe that there were distinct differences in brightness between Titan's northern and southern hemispheres, and polar hoods, that were thought to be seasonal variations.

Voyager's solar and Earth occultation data, acquired as the spacecraft passed through Titan's shadow, revealed that the dominant atmospheric constituent is nitrogen. Methane, the atmospheric gas detected from Earth, represents several per cent of the composition of the atmosphere. There are also hydrocarbons of Acetylene 2.2 parts per million, Ethylene 0.1 parts per million, Ethane 1.3 parts per million, and Propane 0.7 parts per million. Nitrites of Hydrogen cyanide 160 parts per billion, and Cyanoacetylene 1.5 parts per billion were also confirmed.



Titan's surface pressure, one and a half bars, is 50 per cent greater than Earth's in spite of Titan's smaller size. The surface temperature was found to be -180 degrees centigrade, indicating that there is little greenhouse warming. The temperature profile in Titan's atmosphere has a shape similar to that of Earth: warmer at the surface, cooling with increasing altitude up to the tropopause at 42 kilometres (-203 degrees centigrade), then increasing again in the stratosphere.

The Cassini Huygens space probe arrived at Saturn on 1 July 2004 and successfully entered orbit around the planet and promptly send back 'post cards' showing the rings, and Saturn's atmosphere in amazing detail. However, we had to wait until 26 October for Cassini's first real close approach of Titan when the probe passed within 1,200 Km of the moon returning the first close up photographs, while about 1% of the moon's surface were also mapped by radar. The infrared images reveal breaks in the cloud cover and some surface features, while radar determined lava like flows of a cryogenic cold substance. Scientists were excited by the findings since they determined Titan was still geologically active with Volcanic caldera and cryogenic cold volcanoes showing some similarity to the surface of the planet Venus. A person standing on Titan's surface in the daytime would experience a level of daylight of a town or city during twilight with an overcast sky.

Cassini Encounters With Saturn’s Moons
Dates for your diary --- Best flyby dates over the Next 12 months.
Orbit -B Titan .......... 13 Dec 2004 ...... (2,358 km)
Orbit -C Iapetus ..... 01 Jan 2005 ...... (65,000 Km)
Orbit 04 Enceladus .. 09 Mar 2005 ....... (500 Km)
Orbit 12 Mimas ....... 02 Aug 2005 ....... (45,100 Km)
Orbit 15 Tethys ....... 24 Sept 2005 ..... (33,000 Km)
Orbit 15 Hyperion .... 26 Sept 2005 ..... (990 Km)
Orbit 16 Dione ........ 11 Oct 2005 ....... (500 Km)
Orbit 18 Rhea ......... 26 Nov 2005 ..... (500 Km)
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Cassini will next fly by Titan on 13 December at a distance of 2,358 kilometres that will be the last close encounter of 2004, when the Huygens landing site will be confirmed prior to the probes release from its mother-ship on Christmas Eve. The tiny Huygen's craft is expected to enter Titan's atmosphere and begin its decent to the surface on 14 January 2005, coinciding with Cassini's close fly by of the moon at a distance of only 60,000 km.

Much of Huygen's science will take place during its atmospheric decent, which will be relayed to the Cassini craft, then transmitted back to earth's waiting scientists and the media, and If the Huygen's probe lands successfully on Titan it will be a major bonus for the mission.

The Huygen's Lander will be attempting to determine the origin of Titan's molecular nitrogen atmosphere. Planetary scientists want to answer the question: "Is Titan's atmosphere primordial (accumulated as Titan formed) or was it originally accreted as ammonia, which subsequently broke down to form nitrogen and hydrogen?"

If nitrogen from the solar nebula (out of which our solar system formed) was the source of nitrogen on Titan, then the ratio of argon to nitrogen in the solar nebula should be preserved on Saturn's largest moon. Such a finding would mean that we have truly found a sample of the "original" planetary atmospheres of our solar system

The Huygen's probe will also try to detect Lightning on Titan. The extensive atmosphere of Titan may host Earth-like electrical storms and lightning. Although no evidence of lightning on Titan has been observed so far, the Cassini Huygens mission provides the opportunity to determine whether such lightning exists. In addition to the visual search for lightning, the study of plasma waves in the vicinity of Titan may offer another method. Lightning discharges a broad band of electromagnetic emission, part of which can propagate along magnetic field lines as whistler-mode emission.

So exciting times lie ahead

Acknowledgements: I would like to thank NASA/JPL for providing updated physic-chemical data for this news item and for the use of the latest images.

Richard Pearson
Science Correspondant YAHOO Instant Messege ID: richard_pearson2

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<span style='color:purple'>Yahoo Instant Messege ID:</span> <span style='color:blue'>richard_pearson2</span>

We had another thread about exactly this. I'll try to find it and merge them. I think my answer was, with only a few weeks to go, I can wait and see.

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I just discovered this thread today! I didn't know that you had this Update Thread on Titan till I looked at all your postings up till the present day, Richard. I don't know how I could have missed most of them except those in the Alternative Theories thread - The Iron Sun - I may have added a comment or two but the discussion is far above my head!!! :P

I missed your interview with the astronomer so the comments you posted later are rather obscure for me!

I had followed all your posts in the Cassini thread which I found very interesting & I also liked the images you posted , some of which I´ve "robbed", i.e. copied! :P

As our science correspondent I look forward to reading many more of your posts here & to seeing many more images from the probes currently investigating our Solar System - as well as any other images you care to post!

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Fascinating graffical diagram.

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The plot of Titan's atmosphere - or our current model - is interesting in light of plans by JP Aerospace for slow rising ion-powered airships to reach orbit. I am not sure if such would ever work on Earth since orbital velocity is so high, drag would overwhelm any lift. Yet Titan's orbital velocity is a much lower 1675 m/s at an altitude of 625 km - combined with the low gravity surely Titan is the world for Orbiter airships.

Yet perhaps they aren't needed beyond the first forays. The Saturn-Titan Lagrange 1 and 2 points aren't very far away at all - 52,400 km inwards and outwards from Titan with respect to Saturn. A Space Elevator could very easily be built with the centre of mass parked at L1/2 and it would be shorter than the proposed elevator for the Moon. Such a system would open up Titan to colonisation or at least advanced exploration by humans.

Ultimately the immense amounts of nitrogen in Titan's atmosphere could be exported to Mars - if terraforming is ever a serious option for that planet. Immense spheres of gas could be haulled into space and released at the right height for a swingby of Saturn and a plunge in towards Mars.

qraal

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Here is a website exclusively devoted to Titan:
www.titanexploration.com

Here is a website exclusively devoted to Titan:
www.titanexploration.com [/b][/quote]
We know that the Huygens probe is going to land between a dark area and a bright area.If it's on the "dark side" of Titan and not on the opposite side constantly facing Saturn, we have no chance of getting an image with Saturn on the horizon though it's unlikely that Saturn is visible through the deep and opaque atmosphere of Titan.

www.titanexploration.com

12 hours to go till Huygens hits the atmosphere.
I wish the Huygens team good luck on this mission.

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We have a special tv program on at 11.30 on BBC2 in the UK. I will be glued to it. Fingers crossed everyone!!!!

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I've been waiting inmpatiently for months for this Titan mission - now here we are at the "doors" of Saturn´s largest moon, Titan!!! Well done NASA!

I must programme my video for the BBC documentary tonight as I will be working & not be at home to see it!

Thanks Jake for the lowdown!

What will we see? That´s still open to debate - but only for a few more hours!!!

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Don´t we all!!!

Everything has gone according to plan & desire in the Cassini-Huygens Mission up to the present moment, so I ´m sure we will get all & much, much more than we expect from the descent of the Huygens Probe today!!!

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At this point, Huygens has been on the surface for about two hours, and Cassini has just stopped the collection of data. The deep space network confirmed that Huygens had a carrier signal, hopefully Cassini was receiving it. In 100 minutes [15:24 UT], is the first chance of getting data relayed via Cassini. Hopefully, I'll see images before lunch [I'm in US Central Time].

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Oh that's wonderful. Its great to hear that our little probe made out well. I'm really curious as to the location at which he landed. I know the decent times were a bit scketchy depending on atmospheric conditions. I wonder, if he landed quicker than expected, does that mean he'll have more battery and more time to collect surface data before Cassini moves over the horizon?

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i am going to pee my pants look at nasa tv every one
live coverige of the hole thing all day today

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its hard to thank they are probley going to keep it there and let its batterys die i lv that probe

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This BBC program will I'm sure be available to watch at www.bbc.co.uk in a day or so.

I'm sure everyone else is really excited. I've got goosebumps. Lets keep our collective fingers crossed that we get some good data folks!!!

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I've seen a note indicating that they continued to get a signal after Huygens landed, and that the new estimate for the first data arriving at Earth will be in about 35 minutes at 11:30AM EST [16:30 UT].

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another 10 minutes till the first data.. im on the edge of my seat here

Same here. I wonder how long between first data and first image?

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what page are you looking at?

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There are several, but they still don't say much. Just the Cassini/Huygens home pages, and the various news feeds.

I also just encountered my first high-traffic server error, so it appears that NASA's public access computers are not going to be capable of handling the amount of traffic expected in the next few hours. Oh well.

If someone is watching NASA TV, which I can't get here [even via the internet], please give some updates as to what's being received.

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"The probe -- although designed to last only minutes on the moon's surface -- beamed data for nearly two hours to Cassini, in its orbit around Saturn. "

--thats good news!!! ..does this mean thousands of pics?? will we see yoda?? ewoks?? lol ...so i guess this is the biggest day since venus was revealed??

This is a big day! I don't know if it is possible to rank the many big days the various space probes have given us.
- Venera images of the surface of Venus
- Magellan maps of Venus
- Galileo close-ups of Europa
- WMAP map of the CMB
- Voyager images of Miranda & Triton
- Mars MER rovers
- Shoemaker NEAR images of, and landing on, Eros
- etc

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yay!!! sounds like its a success ...we have to see some images tho soon!!!

at 11:33EST, Miles O'Brien [of CNN] entered this in his blog:
This means that it is now about three hours till images arrive [about 3PM EST].

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wow.. okay, i guess this means i will get some amount of work done today.. ive been glued to this topic all morning!

First image from Titan on

http://www.esa.int/SPECIALS/Cassini-Huygens/index.html

Right now

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First pic is from ground level looks like pepple half submerged under a sheen of ice

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Magnificent!!! What a spectacular success for ESA/NASA! Congratulations to both agencies & the joint/combined teams that made this Mission possible!

I was able to watch the BBC programme on my video an hour after it started. (I think I broke all records in getting home from work last night to see it as soon as possible!)

I was too tired to post anything here or to check out people´s posts! I shall be more attentive to the news from Titan all week! The little probe did ever so well & exceed all our expectations!!!

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This is a nice thought. However, Mars no longer has a magnetic field to "protect" the atmosphere. A magnetic field is required to prevent the atmosphere from being eroded by solar winds.