Are we really... Alone?

[Wearden]

Hey guys, I was recently reading a book about Space, Apparently scientists have found a planet that may wield Human life on it in future years.

They were saying that it's current state is the same of what the Earth was so many million years back, Smoky, Full of Lava and Volcanoes and it has a steadily forming Atmosphere.

I shall get back to you on the name of the planet.

 

All the best.

Ben.

[foodchain]

Listen you show me one other solar system with 9 planets (well I guess 8 now) with only one of them having a severe elliptical orbit and the rest (for the most part) circular. I might believe that life COULD form there similar to ours. But I won't say intelligent life.

 

The fact is we live in a messed up solar system that is unlike any other we've seen, on a planet that's nothing like the other 8 (or 7 or whatever) in our system and we're the only highly intelligent life-form out of the millions (an approximation) of species that have come and gone from our planet.

 

Put that in your Drake equation and give it a spin. Our existence is one big WTF after another.

 

Yes but that is factoring in lots of unknowns really. The only life we have been able to study is currently that found on earth, and in earth not all life or where it has adapted to live in is not known also. Just going from the ocean the rate of discovery for new species is rather high, not to mention the environments some of them occupy is actually deadly to anything previous to it. Plus going from Hanford, Washington, bacteria has found a way to survive in toxic waste and extreme heat. The other idea is that evolution may have made the current molecular or biochemical reality of life something so eroded if you will from the early means that basically reverse engineering such is probably highly unlikely, and that the traces of evolution will suffer from such unless very primitive life is fossilized somewhere. Going from records in time it was millions of year gaps in the most primitive life, such as bacteria making any real changes past that stage, I doubt many people can actually envision millions of years of time passing really. So this is problematic is some regards, in that life of all things might have formed in very small or in the nano scale inside of rocks somewhere developing a cell wall that’s sort of like how stainless steel has a natural oxide layer, but such is purely speculative of course.

 

Then when you move onto statistics this takes a root in thought because we can only use the frame of biological understanding we currently hold, which is life on earth in which to gauge how life could come about or exist really without speculation, somewhat like movies similar to aliens, which is a cool series of movies really, but that is off topic.

 

Now without knowing for certain conditions that can lead to "life" or what the ultimate definition of such is even its really hard to quantify such. Now here is another loop, how many planets exist in the universe? How many solar systems? I would have to say the number of such is probably close to the statistics actually, so for every billion planets you get a condition that favors life, or for every two billion, I mean what’s the number and what empirical data actually supports this quantitative statement?

 

I am still very interested in the idea that mars may have been starting life, more so for all the information that could give us, more so knowing about the geology of mars and its place in the solar system. I mean they found bacteria on a rock from mars, it was fossilized and in regards to size the only other life that was found to match it was found in Australia, and the mars rock was far removed from that location, but overall taking everything into consideration, such as the rock even had traces of biological processes, that it was not conclusive enough to rule it as life from mars.

[SkepticLance]

To foodchain.

 

One of the great unknowns in these debates is the set of conditions needed for biogenesis - to allow life to appear in the first place. This is a totally different question to that of the conditions permitting evolution.

 

I have often seen the argument based on extremophiles. That is; if life can exist over such a wide range of conditions here on Earth, then it must be able to do likewise over a wide range of planets. However, since we do not know what the conditions are for biogenesis, the argument in invalid. Biogenesis may be possible only under a very restricted set of conditions, that occurred here on Earth just once by a freak situation, and have not been seen anywhere else in our galaxy anywhere. Or else, biogenesis is possible under all sorts of conditions, and happens on every second planet. We just do not know.

 

How many planets in our galaxy? There appears to be about 10,000,000,000 star systems. The sampling of nearby star systems to date would imply planets on pretty much all star systems. However, that sampling would also suggest that systems like our own are rare. Lots have giant planets in close orbit about the star. One theory says that Jupiter in its current orbit was needed for life, since it mopped up assorted debris, thus protecting the Earth from lethal bombardment. Jupiter-like planets are apparently rare. The other common feature in extra-solar planets is elliptical orbits. A circular orbit may be needed for life, since it provides liquid water all year round.

 

If these implications are true and widespread, then life itself may be rare.

[foodchain]

To foodchain.

 

One of the great unknowns in these debates is the set of conditions needed for biogenesis - to allow life to appear in the first place. This is a totally different question to that of the conditions permitting evolution.

 

I have often seen the argument based on extremophiles. That is; if life can exist over such a wide range of conditions here on Earth, then it must be able to do likewise over a wide range of planets. However, since we do not know what the conditions are for biogenesis, the argument in invalid. Biogenesis may be possible only under a very restricted set of conditions, that occurred here on Earth just once by a freak situation, and have not been seen anywhere else in our galaxy anywhere. Or else, biogenesis is possible under all sorts of conditions, and happens on every second planet. We just do not know.

 

How many planets in our galaxy? There appears to be about 10,000,000,000 star systems. The sampling of nearby star systems to date would imply planets on pretty much all star systems. However, that sampling would also suggest that systems like our own are rare. Lots have giant planets in close orbit about the star. One theory says that Jupiter in its current orbit was needed for life, since it mopped up assorted debris, thus protecting the Earth from lethal bombardment. Jupiter-like planets are apparently rare. The other common feature in extra-solar planets is elliptical orbits. A circular orbit may be needed for life, since it provides liquid water all year round.

 

If these implications are true and widespread, then life itself may be rare.

 

That was my point actually, that we don’t know fully what’s required for life to exist or what forms it can exist in, thank you though.

[JohnB]

The other common feature in extra-solar planets is elliptical orbits.

SkepticLance, could it be that planets in an elliptical orbit are easier to find than those in circular orbits? Given the rather primitive methods we have for detecting them in the first place?

 

Not a rebuttal, just wondering.

[SkepticLance]

To JohnB

 

I really do not see how it could be easier to find planets with elliptical orbits. The two main methods are :

1. Observing the movement of a star, and seeing if it 'wobbles' in its path, showing the gravitational effect of an orbiting planet.

2. Seeing how the light of a star dims as a planet passes in front of it.

 

Neither method would be different for circular versus elliptical orbits.

 

The major distortion in our knowledge comes from the fact that we can easily detect large planets, but little ones (like Earth size) are much harder to detect. Thus, we have a distorted picture of lots of stars with large planets and very few small. The reality is likely to be very different.

[Klaynos]

To JohnB

 

I really do not see how it could be easier to find planets with elliptical orbits. The two main methods are :

1. Observing the movement of a star, and seeing if it 'wobbles' in its path, showing the gravitational effect of an orbiting planet.

2. Seeing how the light of a star dims as a planet passes in front of it.

 

Neither method would be different for circular versus elliptical orbits.

 

The major distortion in our knowledge comes from the fact that we can easily detect large planets, but little ones (like Earth size) are much harder to detect. Thus, we have a distorted picture of lots of stars with large planets and very few small. The reality is likely to be very different.

 

1. Which I think from a presentation I saw a couple of months ago is the main method.

 

If the orbit is eliptical, for an object that has the same energy as one that is not eliptical will cause a greater wobble, because of the distances variying as well as the position. Although it will also cause less wobble, depending from where you view them from. So on average it'll be the same, but the easiest ones to find are the big ones with really eliptical orbits with the orbit oriantated the correct way, with the long axis I think angled towards us....