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Coffee House => Coffee House Boards => CH / Science and Technology => Topic started by: odin on January 09, 2005, 11:10:57 AM
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Just a few (http://www.esa.int/esaCP/SEMWRK3AR2E_index_0.html) more days! (http://saturn.jpl.nasa.gov/news/features/feature20050107.cfm) Jan. 14th we'll know if ESA is going to be successful this time.
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Hum,
Splash, thud or sink...?
Can’t wait for the decent shots...
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Let's hope they are indeed decent shots.
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How many lighthours is Saturn removed from us at the moment anyway?
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Hum,
1.2 billion kilometres separate the Cassini spacecraft and Earth - so only 1 hour and 8 minutes for the signal to reach us...
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X-ray wrote:
Let's hope they are indeed decent shots.
Some of the orbital shots on the ESA website are already pretty good. Surface detail is visible when photographed using wavelengths to which the cloud is transparent.
It should be interesting to see what chemicals are found in the atmosphere. Titan has been on a very low "simmer" for the current lifespan of the solar system, too cold for any quick chemistry but even the meagre light that reaches it is sufficient to drive some photochemical processes in the atmosphere.
In a few aeons it should warm up nicely. If the helium burning phase of the Sun lasts long enough, it might get a few creepy crawlies of it's own. Of course, if we haven't left (or destroyed ourselves) by then, we'd be to cindered to notice ;-)
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Karlos wrote:
X-ray wrote:
Let's hope they are indeed decent shots.
Some of the orbital shots on the ESA website are already pretty good. Surface detail is visible when photographed using wavelengths to which the cloud is transparent.
It should be interesting to see what chemicals are found in the atmosphere. Titan has been on a very low "simmer" for the current lifespan of the solar system, too cold for any quick chemistry but even the meagre light that reaches it is sufficient to drive some photochemical processes in the atmosphere.
In a few aeons it should warm up nicely. If the helium burning phase of the Sun lasts long enough, it might get a few creepy crawlies of it's own. Of course, if we haven't left (or destroyed ourselves) by then, we'd be to cindered to notice ;-)
/me starts selling plots on Titan :-D
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I've been looking forward to this ever since I first heard about Cassini on "The Sky at Night". It's quite exciting, the culmination of years of planning, not to mention actual travel time to Saturn.
I wonder what they'll find? Will it be freezing cold hydrocarbon soup lakes? Will it be ammonia ice? Titan doesn't give it's secrets up easily and the heavens have a way of springing a few surprises for us every time.
I can't wait for us to send a probe to Europa, I'd pay money to know what's under that ice. That Jupiter's gravity can supply enough energy to drive Io into a barely stable volcanic world must mean that Europa's core is quite active too, possibly causing hot geothermal vents to pour into the sub-surface oceans, and where there's warmth and energy on Earth, there's life...
It kind of gets me back in touch with the fascinated schoolboy in me that watched Columbia rise into the sky on TV on 12 April 1981 with barely contained enthusiasm, or when I spent my early years pouring over facts and statistics from the Apollo missions.
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PMC wrote:
I've been looking forward to this ever since I first heard about Cassini on "The Sky at Night". It's quite exciting, the culmination of years of planning, not to mention actual travel time to Saturn.
I wonder what they'll find? Will it be freezing cold hydrocarbon soup lakes? Will it be ammonia ice? Titan doesn't give it's secrets up easily and the heavens have a way of springing a few surprises for us every time.
I can't wait for us to send a probe to Europa, I'd pay money to know what's under that ice. That Jupiter's gravity can supply enough energy to drive Io into a barely stable volcanic world must mean that Europa's core is quite active too, possibly causing hot geothermal vents to pour into the sub-surface oceans, and where there's warmth and energy on Earth, there's life...
It kind of gets me back in touch with the fascinated schoolboy in me that watched Columbia rise into the sky on TV on 12 April 1981 with barely contained enthusiasm, or when I spent my early years pouring over facts and statistics from the Apollo missions.
We're all keen to know what's under Europa's Ice, but we can send a probe there for fear of contaminating it with Earth life.
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There was talk about building an eventual probe on ISS, to minimize the risk of contamintating it.
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bloodline wrote:
We're all keen to know what's under Europa's Ice, but we can send a probe there for fear of contaminating it with Earth life.
It's why Galileo was sent crashing into Ganymede (or was it Callisto or Io?), so that it wouldn't risk crashing into Europa and contaminating the place.
Remember that Apollo 12 brought back pieces of Surveyor 3, which had been sitting on the moon for three years and was still harbouring live micro-organisms! They're suprisingly hardy little critters and we have a duty to ensure that what will one day becomes space junk won't contaminate other worlds.
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I don't remember which moon it crashed into, but Io would be a good place. It orbits within an absolutley lethal radiation belt chock full with charged particles. It's literally riding through a taurus of ions.
The other moons are rock/ice and orbit above this radiation belt (Europa still gets washed with the occasional ion storm) - you could easily contaminate those.
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@Karlos,
I think you're right. I'm sure I recall that Galileo was sent spiralling through Io's ion belts to scrub it before it was deliberately crashed.
No doubt Blobrana would put the record straight on this one!
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we have a duty to ensure that what will one day becomes space junk won't contaminate other worlds
Quite the contrary; It's our duty to contaminate as many worlds as possible. We cannot live on such worlds, but some Earth-organisms would thrive there.
It's all about evolution; survival of the fittest and all of that.
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whabang wrote:
we have a duty to ensure that what will one day becomes space junk won't contaminate other worlds
Quite the contrary; It's our duty to contaminate as many worlds as possible. We cannot live on such worlds, but some Earth-organisms would thrive there.
It's all about evolution; survival of the fittest and all of that.
Yes, but we can only do that after we have made sure that there isn't already something else there.
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whabang wrote:
Quite the contrary; It's our duty to contaminate as many worlds as possible. We cannot live on such worlds, but some Earth-organisms would thrive there.
It's all about evolution; survival of the fittest and all of that.
Statistically speaking, that fittest isn't likely to be us when you take the whole galaxy into account. ;-)
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Well, we DO fit in the galaxy, don't we? :crazy:
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@PMC
>>wonder what they'll find?
Hum,
Hydrocarbon rain that’ll cover the camera lenses… (Weird rain, that is ten times bigger than earth’s raindrops and they fall down a lot slower…)
But before that, as it settles on the soft `mud` it’ll pick up the faint glow of Saturn through the green sky.
And yeah, Galileo passed through the ion belt before it burned up. Though the fiery entry, as well as the huge atmospheric pressures would zap most stowaways.
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Greetings,
I hope they'd find some life out there. We *nearly found one in Mars. Hope to expect one here. Besides, the least traces of it would be fine, but I doubt. :-(
Regards,
Gizz
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I love the description Blob. I too sort of imagine a world where waxy hydrocarbon slush squishes underfoot and falls from the dark sky...
One wonders what Titan would be like if it were orbiting our own Earth, being that much closer to the sun would it have spawned life of any kind? The building blocks are there on Titan, but it's way too cold for life to exist there.
I'd bet that Esso would have built it's first moonbase by now.
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I'd bet that Esso would have built it's first moonbase by now.
Hmmm... Diesel powered Space craft? :-D
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Well, jet fuel isn't as combustable as petrol for example. IIRC some rockets have used Kerosine and even Aluminium powder... Not sure if they've successfully used diesel though.
O/T - the jet fuel used for the SR-71 spyplane requires very high temperatures in order to combust. If you were to drop a lit match into a bucket full of SR-71 fuel, the match would be extinguished, and popular legend has it that if you threw the bucket of fuel onto a barbecue, the barbecue would go out too.
Anyway, Titan would have some strange properties. Because of the overwhealming abundance of hydrocarbons, you could create a reverse bunsen burner by pumping pure oxygen into the atmosphere and combusting it...
One of Arthur C Clarke's novels describes life on an underground colony on Titan. I forget what it's called now but the central character travels to Earth to celebrate the 500th anniversary of the Declaration of Independance.
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PMC wrote:
I love the description Blob. I too sort of imagine a world where waxy hydrocarbon slush squishes underfoot and falls from the dark sky...
One wonders what Titan would be like if it were orbiting our own Earth, being that much closer to the sun would it have spawned life of any kind? The building blocks are there on Titan, but it's way too cold for life to exist there.
Titan would likely not survive such proximity to the sun.
First of all, its gravitational pull* is just enough to hold on to the atmosphere it has at -180C. The RMS speed of the molecules at that temperature is sufficiently low to prevent the gases simply escaping.
Even then, a small fraction of the atmosphere does escape, since statistically you'll always get some molecules moving fast enough and even at Saturn's distance there is still some solar wind scavenging. Luckily for Titan, the gas tends not to escape the gravitational pull of Saturn, producing an equilibrium effect where Titan is able to recapture most of this loss.
If Titan orbited the earth, the increased temperature would push a significant quantity of the atmospheric gases RMS speeds above escape velocity. Even without the solar wind to make the effect worse, the atmosphere would most likely quickly diminish.
*the gravitational pull actually depends largely on this last part...
Lastly, whilst not fully confirmed, the moon seems to be made of a rock-ice mixture that is common for bodies in the outer solar system. If it were heated to terrestrial temperatures, the ice would simply melt. Stripped of it's atmosphere, the water would evaporate pretty quickly leaving you with just the rock content.
OTOH, if Titan turns out to be mostly rock, its mass and subsequent surface gravity will be a lot higher and the above 'worst case' scenario alleviated somewhat.
When the sun begins its helium burning phase, the solar output will increase dramatically. Titan will be warmed up significantly and it will still have the benefit of Saturn's gravitational trap to help keep its atmosphere. After aeons of 'slow chemistry', it could become quite active.
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PMC wrote:
Well, jet fuel isn't as combustable as petrol for example. IIRC some rockets have used Kerosine and even Aluminium powder... Not sure if they've successfully used diesel though.
AFAIK, there were plans to build a rocket powered by Aluminium powder, but since solid fuel is hardly managable in a rocket (you know, bits stucking in pumps and nozzles and so) they changed to kerosine/hydrogen
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Actually, aluminium 'dust' is one of the finest grain materials you can make. It would be fairly trivial to suspend in kerosene and behave entirely liquid-like. Still I'd rather not have aluminium oxide pouring out the exhaust of an engine...
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@Speel
I think they use Aluminium powder in the shuttle's solid fuel boosters.
The shuttle is unique in being the only manned space vehicle with solid fuel boosters, all others being liquid fuelled. As you correctly point out, solid fuel isn't manageable and you can't "throttle back". In essence you're riding a large firework.
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KennyR wrote:
Statistically speaking, that fittest isn't likely to be us when you take the whole galaxy into account. ;-)
No, but some primitive bacteria might be. :-D
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Greetings,
Quote:
KennyR wrote:
Statistically speaking, that fittest isn't likely to be us when you take the whole galaxy into account. ;-)
Quote:
whabang wrote:
No, but some primitive bacteria might be. :-D
Care to point *where in the galaxy besides Earth and Mars? :-)
I think, Europa hold the key to life, possibly. http://people.msoe.edu/~tritt/sf/europa.life.html
Regards,
GiZz72
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Speelgoedmannetje wrote:
Well, we DO fit in the galaxy, don't we? :crazy:
Sagan said we were all made of "Star Stuff"
i think that's beautiful!
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Greetings,
cecilia wrote:
Speelgoedmannetje wrote:
Well, we DO fit in the galaxy, don't we? :crazy:
Sagan said we were all made of "Star Stuff"
i think that's beautiful!
@cecilia
I used to watch his documentary 'COSMOS' long ago. I was facinated the way he tells stories about the universe. He was descibing about the acient people, the planets, comets, meteors and spac explorations, If I recall. I just wonder if you have seen all episodes. Too bad it never get to show that here(locally) anymore. Most of the information there were outdated by now, I guess. :-)
Regards,
GiZz72
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Hum,
[color=ff00ff][/color]
Look for the girl with the sun in her eyes...
All the carbon in the Universe, including that needed for carbon-based life forms such as ourselves, has been made in the hearts of stars - through what is known as the "triple alpha reaction" - where three helium nuclei (alpha particles) fuse to make to make a nucleus of carbon-12...
We are indeed `lucy in the sky with diamonds`
[color=ff00ff][/color]
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blobrana wrote:
Hum,
[color=ff00ff][/color]
Look for the girl with the sun in her eyes...
All the carbon in the Universe, including that needed for carbon-based life forms such as ourselves, has been made in the hearts of stars - through what is known as the "triple alpha reaction" - where three helium nuclei (alpha particles) fuse to make to make a nucleus of carbon-12...
We are indeed `lucy in the sky with diamonds`
[color=ff00ff][/color]
How romantic!
:love:
Cheers Blob, I'll remember to drop that one into coversation with my g/f, it'll win some brownie points hehe.
I too used to watch "Cosmos" at a very young age and appreciated Sagan's unique presentation style. I also read "Broca's Brain" which made for fascinating reading for a twelve year old...
Would be nice to see "Cosmos" rerun. Anyway, it's time to go and see how Huygens is getting on... Fingers crossed...