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Argos
2002-May-20, 08:43 PM
According to Nature (http://www.nature.com/nsu/020513/020513-3.html), one out of every three Earthlike planets may harbor life. So, things like these are more likely to succeed.

www.geocities.com/Area51/Dimension/5189/extracom.htm


<font size=-1>[edited by Argos on 2002-07-10 to add the word "Earthlike"]</font>

<font size=-1>[ This Message was edited by: Argos on 2002-07-10 09:53 ]</font>

Jigsaw
2002-May-21, 02:31 AM
Wonderful--they're going to beam conspiracy theories to the stars. /phpBB/images/smiles/icon_biggrin.gif

Our personal report on the human condition will expose how the majority of the intelligent creatures of the planet are kept out of the system by the local powers.

Ad Hominid
2002-May-21, 10:02 AM
On 2002-05-20 22:31, Jigsaw wrote:
Wonderful--they're going to beam conspiracy theories to the stars. /phpBB/images/smiles/icon_biggrin.gif


Eek! They'll exterminate us for sure now.

Conrad
2002-May-21, 10:48 AM
On 2002-05-20 22:31, Jigsaw wrote:
Wonderful--they're going to beam conspiracy theories to the stars. /phpBB/images/smiles/icon_biggrin.gif

Our personal report on the human condition will expose how the majority of the intelligent creatures of the planet are kept out of the system by the local powers.


Okay, that excludes the dolphins and chimpanzees, now what about Hom Sap?

Pi Man
2002-Jun-30, 02:46 AM
So-- Um... two others of the planets within our solar system may harbor Murcureans or Venisuns or Martians or Jupiterians etc...?

/phpBB/images/smiles/icon_confused.gif

P.S. don't forget those Neptune Men from the ever lovable movie Invasion of the Neptune Men.

Espritch
2002-Jun-30, 04:45 PM
So-- Um... two others of the planets within our solar system may harbor Murcureans or Venisuns or Martians or Jupiterians etc...?

Technically, the Nature article said that 1 in 3 "earth like" planets could harbour life. Unfortunately, the article didn't actually define "earth like". One could argue that Venus is earth like in that it is nearly the same size and orbits the same type of star (or in this case, the same star) at a "relatively" similar distance.
One could also argue that it is not at all earth like since it has no moon, a crushingly thick atmosphere, sufuric acid cloulds, and surface temperatures hot enough to melt lead.

xriso
2002-Jun-30, 06:01 PM
On 2002-06-30 12:45, Espritch wrote:
Technically, the Nature article said that 1 in 3 "earth like" planets could harbour life. Unfortunately, the article didn't actually define "earth like". One could argue that Venus is earth like in that it is nearly the same size and orbits the same type of star (or in this case, the same star) at a "relatively" similar distance.
One could also argue that it is not at all earth like since it has no moon, a crushingly thick atmosphere, sufuric acid cloulds, and surface temperatures hot enough to melt lead.


Hmm... I wonder if earth-like planets in hostile conditions would count as earth-like in
their definition. Supernova prone places in a galaxy would probably be dead zones, and
likewise for high-debris solar systems (if such things do form). Of course, if all
you're looking for is ANY life, you may find this 1/3 ratio (which is much too optimistic
in my opinion). As for advanced life, however...

Pi Man
2002-Jun-30, 06:33 PM
On 2002-06-30 12:45, Espritch wrote:

Technically, the Nature article said that 1 in 3 "earth like" planets could harbour life. Unfortunately, the article didn't actually define "earth like". One could argue that Venus is earth like in that it is nearly the same size and orbits the same type of star (or in this case, the same star) at a "relatively" similar distance.
One could also argue that it is not at all earth like since it has no moon, a crushingly thick atmosphere, sufuric acid cloulds, and surface temperatures hot enough to melt lead.


So, the article in Nature didn't actually tell us anything new? Depending on what "Earth like" means it could be very slightly less than one in three or it could be very slightly more than one in 3 hundred billion gazillion caboballion. Darn!

Kaptain K
2002-Jun-30, 07:31 PM
It seems to me that since Earth has life, 100% of all earthlike planets would have life, by definition!


<font size=-1>[ This Message was edited by: Kaptain K on 2002-06-30 15:36 ]</font>

jaydeehess
2002-Jul-07, 04:42 AM
Espritch (quote) One could argue that Venus is earth like in that it is nearly the same size and orbits the same type of star (or in this case, the same star) at a "relatively" similar distance.

I always figured that Venus would make a better candidate for terraforming but Mars gets all the hype. Venus just has much more raw material to work with.

Oh and for other planets in our own system lets not leave out Saturn's moon, Titan. It may be a bit chilly but it does have a wealth of organic molecules.

Earthlike.... quite a subjective description for a magazine of scientific repute.

Espritch
2002-Jul-07, 05:19 AM
I always figured that Venus would make a better candidate for terraforming but Mars gets all the hype. Venus just has much more raw material to work with.

Possibly. But before I invested much effort into terraforming Venus, I would want to make sure the Catastrophic Volcanism hypothesis isn't true. That's the one that explains the apparent young appearance of the entire surface of Venus as a result of a volcanic cycle consisting of long periods of inactivity intersperced by catastrophic events wherein virtually the entire crust of the planet melts and gets reformed.

It would be a major bummer to get an eco-system up and running on Venus only to have the whole thing blasted by magma.

Rift
2002-Jul-07, 04:37 PM
I always figured that Venus would make a better candidate for terraforming but Mars gets all the hype. Venus just has much more raw material to work with.



There is one major problem though. Venus has a day which is 243 days long... The day on Mars is almost the same as earth.

David Hall
2002-Jul-07, 06:26 PM
The real question is which one would be easier to terraform?

Venus has this terribly thick, caustic atmosphere which must be dealt with before we could do anything else. We can't even land on the surface until we can take care of it. Somehow, we'd have to remove something like 90% of the CO2. Then we'd have to wait for the planet to cool down. Then we'd have to deal with problems like mentioned above.

As for Mars, we'd have to add atmosphere. Some think the secret is simply to melt the poles to add CO2 and water vapor. Extra atmosphere would raise the temperature, perhaps above the freezing point of water. Then we'd have a fairly easy time of working the surface and converting the atmosphere to breatheablity.

I think Mars would be easier and take less time, so that's why most people focus on Mars first.

Kaptain K
2002-Jul-08, 12:20 AM
The problem with Mars is that Mars doesn't have an atmosphere because it isn't big enough to hold one. So, even if we could melt the polar caps, etc., the atmosphere that we created would gradually leak off into space and once it's gone, it's gone for good. There would be no way to do it again.

With Venus however, once the CO2 (and H2SO4) are eliminated, keeping it that way would be a maintenance problem.

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<font size=-1>[ This Message was edited by: Kaptain K on 2002-07-07 20:25 ]</font>

Pi Man
2002-Jul-09, 09:49 PM
On 2002-07-07 12:37, Rift wrote:

I always figured that Venus would make a better candidate for terraforming but Mars gets all the hype. Venus just has much more raw material to work with.

There is one major problem though. Venus has a day which is 243 days long... The day on Mars is almost the same as earth.


243 days long? I could not stay up for 5832 hours straight.

jaydeehess
2002-Jul-10, 01:25 AM
243 "day" long days. So what. I worked in the high Arctic. You get used to it.

All you have to do to Mars is add an atmosphere! It's gotta be generated from something or shipped in from somewhere. If it is shipped in from.... the asteroid belt, it's gonna cost ya big time.

Venus on the other hand merely(slight sarcasm) needs to have some of it's present atmosphere bound up chemically. Floating dirigible like machines that bind the carbon atoms from CO2 and the sulfur oxide ion from the H2SO4. Now it's been a long time since chemistry classes but you end up with H2O, O2, and C(SO4)2 I believe. You reduce the acidity and CO2 content of the atmosphere.

Now a catastrophic volcanism setting would indeed be a real downer here but if you could at least get the temp and pressure down to a level wherein you can land long lived probes you can investigate the seismic activity before a commitment to all out terraforming.

Back to a 243X24 hour long day. With it's warmer clime and new, fresh lakes AND long periods of daylight ,it would make a real nice vacation spot.

honestmonkey
2002-Jul-10, 02:18 PM
I recall an old article by Jerry Pournelle, in which he suggested sending specially bred bacteria to Venus that would do the work of reducing the atmosphere for us. You seed the top layers, the microbes do some work, a dozen years or so go by and you seed again with different microbes designed to do more work on the lower atmosphere. Eventually you end up with a planet that is slightly on the cool side but with a breathable (for humans) atmosphere. All this for the cost of a few rockets over the course of a century. Then (barring volcanic cataclism) we'd have a whole new planet to explore.

Pi Man
2002-Sep-03, 08:07 PM
On 2002-07-09 21:25, jaydeehess wrote:
243 "day" long days. So what. I worked in the high Arctic. You get used to it.


Has anybody seen the movie, Insomnia? The arctic might be good training grounds for the first colonists on Venus. Otherwise, NASA would have to invest in sunlight simulating lightbulbs for the colonists.

JS Princeton
2002-Sep-03, 11:45 PM
Terraforming of Mars was proposed by one of my professors as something that should be initiated immediately. We would need approximately 18 Saturn V rockets to send 8 colonists with one-way tickets to Mars with the mission to a) develop Martian resources and b) be fruitful and multiply. At first, they would be in self-survival mode, but eventually they could move onto more ambitious projects. If done right, the cost could be on the order of magnitude of the Apollo missions, but the long-term rewards are plainly phenomenal.

JS Princeton
2002-Sep-03, 11:47 PM
Venus also has the problem right now of a surface temperature that would melt lead. You'd have to do some reverse-greenhouse effect before anybody's going to land there.

Mars can get started right away.

overrated
2002-Sep-04, 12:34 AM
Seems to me like the chief issue is money. National priorities are so much different than they were in the 60's in many ways. And you can't say "we have to beat the terrorists by going to Mars!" in the same way you could say "we have to beat the Russkies by going to the Moon!" So although none of these projects are outside the realm of possibility, all would take the kind of national focus--and funding--that the Apollo project enjoyed. Unfortunately, in my opinion, our administration seems bent on making NASA do less and less with, well, less and less....

GENIUS'02
2002-Sep-04, 12:56 AM
On 2002-07-09 21:25, jaydeehess wrote: Floating dirigible like machines that bind the carbon atoms from CO2 and the sulfur oxide ion from the H2SO4. Now it's been a long time since chemistry classes but you end up with H2O, O2, and C(SO4)2 I believe. You reduce the acidity and CO2 content of the atmosphere.



I can't find a way to ballance your equation, unless maybe the sulphate ion becomes a sulphite ion; i.e from SO4(-2) --> SO3(-2)
then you'd get:
2H2SO4 + CO2 ---> 2H2O + O2 + C(SO3)2
that ballances, but somehow i don't remember ever seeing this equation in my chemistry clases, and i have never heard of carbosulphite or whatever it would be called.

oh i just found a molecule of formular (C24)+SO3(OH)- but it requires graphite and a mixture of acids to do.
_________________
its amazing how in the space of a few months, the memory can be serverly damaged, and all that you once knew is now hearsay and you know.... notmuch.

<font size=-1>[ This Message was edited by: GENIUS'02 on 2002-09-03 21:05 ]</font>

JS Princeton
2002-Sep-04, 03:04 PM
Sorry, I don't think carbon sulfate or carbon sulfite is ever chemically favored. To get carbon to reduce to that extent would be, well, very difficult in the conditions outlined. If you want to reduce carbon you need to have some external energy source (such as light from the sun in plant photosynthesis) and it helps to be able to polymerize (such as making sugar).