- #1
willstaruss22
- 108
- 1
What are the inner and outer limits of the habitable zone in distance for the sun?
willstaruss22 said:Im my mind i would think that if Earths atmospheric pressure was raised to 2 bar it would raise the boiling point making the habitable zone closer to the sun. Even if there were more clouds in the atmosphere they would reflect more of the suns rays making the zone closer as well. The albedo of Venus is .70 while Earth is .30-.35 which means Earth receive more sunlight.
Life could exist at 3au if it evolved there but the ecology of that life system would be very different to that of the earth. The length of the days and years are intrinsically bound up with life forms on earth. If for some reason the Earth moved to 3AU with or without the moon I believe 99.9% of life on Earth would cease to exist for a myriad of ecological and biological,seasonal reasons, but having said that, some forms life would likely "find a way" and evolve on a different evolutionary ladder.willstaruss22 said:What are the inner and outer limits of the habitable zone in distance for the sun?
I agree Damo, we seem to have hit a billion to one sweet spot. What I wonder are the odds that it exists anywhere else in the universe? The thought that we are alone is a very foreboding one don't you think!?Damo ET said:The other thing to take into consideration is that the Earth has a molten iron outer core which gives 'us' a magnetosphere. This prevents our delicate atmosphere from being blown away by the solar wind! Take away 'our' magnetic field, and life as we know it here would be vastly different regardless where we sit in the habitable zone.Damo
Velikovsky said:I agree Damo, we seem to have hit a billion to one sweet spot. What I wonder are the odds that it exists anywhere else in the universe? The thought that we are alone is a very foreboding one don't you think!?
Velikovsky said:Most people envisage highly sophisticated extraterrestrials with advanced warp-drive ect, how often do people consider that the Human race are in fact the most advanced beings in the universe?
I agree whole heartedly. Life, and intelligence are 2 vastly different things as we are well aware. I would expect that anyone with a basic understanding of the evolutionary process on our planet (which has enabled life to get to the stage where it is today), wouldn't be expecting any life we potentially find in the nearest 1000 suitable systems to contain anything more than the simplest bacteria, if anything at all.Velikovsky said:I don't disagree that there's a possibility Damo, after all "we" happened. It's the probability of life even remotely evolving along our lines. Most people envisage highly sophisticated extraterrestrials with advanced warp-drive ect, how often do people consider that the Human race are in fact the most advanced beings in the universe?
Damo ET said:wouldn't be expecting any life we potentially find in the nearest 1000 suitable systems to contain anything more than the simplest bacteria, if anything at all.
It might be possible that at the present time we may be the most advanced species in our Galaxy, but that will be dependent on a few things. If interstellar space travel proves to be the massive hurdle it appears to us to be at present (which affects all intelligent species around the Milky Way the same),
Damo
An asteroid cannot destroy a whole solar system, but intelligent life can destroy (or even use) an asteroid.Damo ET said:If interstellar space travel proves to be the massive hurdle it appears to us to be at present (which affects all intelligent species around the Milky Way the same), and there is no solution to the practical speed limits imposed by physics regardless of technological advances, this would mean that any intelligent species could be wiped out completely by one single asteroid, never to explore again.
Life exists everywhere on our planet (excluding the molten interior), and there are indications that life from Earth might be able to live permanently on Mars. I would not call this "sensitive" - we don't even know where the limit of our life is. Life which evolved in different conditions would be able to adapt to different conditions.julcab12 said:Life in general is extremely sensitive. Even the simplest 'hardcore' lifeforms (extremophiles) are prone to temperature and pressure.
mfb said:and there are indications that life from Earth might be able to live permanently on Mars. I would not call this "sensitive" - we don't even know where the limit of our life is. Life which evolved in different conditions would be able to adapt to different conditions.
mfb said:Sure, you cannot take a bacterium which is adapted to live in rocks 3km below the surface and expect it to survive somewhere in the antarctic ocean. So what?
I don't get your point. There is no place where all organisms can survive. How does that matter if we consider places where life is possible?until given the opportunity(It will happen eventually) to adapt gradually under conditions(local/General) while most of them died and became extinct.
If Mars is similar to Earth, there are similar planets on many stellar systems.Case of Mars. In general. It is different to Earth but such local criteria has similarity to Earth which is compatible to certain life.
http://www.digitaljournal.com/article/343021The astronomers concluded from the statistics that 6 percent of all red dwarf stars may have an Earth-like planet.
Sure. Life on other planets will be adapted to the conditions of that planet, as it always faced those conditions during its evolution.Well. Adaptation-mutation is a gradual process you don't expect a fish to develop limbs or wings overnight (Tiktaalik roseae) or drain your fish tank and expect them to grow limbs or more so survive . Same is true with bacterium adaptation?
mfb said:I don't get your point. There is no place where all organisms can survive. How does that matter if we consider places where life is possible?
There is no place on Earth where life is impossible (again, excluding the molten interior).
What is "P-life"?
If Mars is similar to Earth, there are similar planets on many stellar systems.
http://www.digitaljournal.com/article/343021
Sure. Life on other planets will be adapted to the conditions of that planet, as it always faced those conditions during its evolution.
mfb said:What is "P-life"?
mfb said:If Mars is similar to Earth, there are similar planets on many stellar systems.
http://www.digitaljournal.com/article/343021
mfb said:An asteroid cannot destroy a whole solar system, but intelligent life can destroy (or even use) an asteroid.
The average lifetime of intelligent and technological species is a completely unknown factor. Is it of the order of 100-1000 years, because they all tend to kill themselves as soon as nuclear power and similar things are available? Is it of the order of millions of years? Is there a reasonable probability that the species (or some descendants) will exist for billions or trillions of years?
Sure, but you were taking about interstellar travel as (potential) barrier. Interplanetary travel is easy compared to that.I agree, a single asteroid connot destroy a whole solar system, but as an intelligent species in which we gauge all possible others against ourselves, our entire 'intelligent' civilization could be wiped out by a single asteroid!
A restart might be tricky - raw materials would be harder to obtain compared to the initial development, as the cheapest sources are exploited now.I would think that although we may 'destroy' ourselves, the human species wouldn't be completely wiped out. We may delay ourselves technologically for a while, but we would still have the runs on the board to progress again quickly.
willstaruss22 said:I just find it intesting that Earth is considered on the inner part of the zone when we have had ice ages that covered a great deal of our planet.
mfb said:Sure, but you were taking about interstellar travel as (potential) barrier. Interplanetary travel is easy compared to that.
Planets close to the sun are easier to detect, not harder - the Doppler shift increases. In general, the transit probability goes up, too, but for Earth and Alpha Centauri no transits happen.Assuming their astronomers have discovered our world (its questionable considering how close we are to our sun)
With an established frequency to transfer data, we would be able to get a reasonable data rate even with current radio telescopes.4.36 light years away and even if we each knew the other existed we would probably not be able to do anything more then guess if there was life there.
The habitable zone, also known as the Goldilocks zone, is the region around a star where it is possible for a planet to have liquid water on its surface. This is considered a key factor in determining a planet's potential to support life.
The boundaries of the habitable zone are determined by the distance from the star and the star's luminosity, or brightness. The closer a planet is to a star and the more luminous the star, the warmer the planet will be. Therefore, the habitable zone is typically located within a specific range of distances from the star.
Liquid water is important for habitability because it is necessary for the existence of life as we know it. It is a universal solvent and is essential for various biochemical reactions that sustain life. Without liquid water, it is unlikely that life could exist on a planet.
Yes, a planet can exist outside of the habitable zone. However, it is less likely for that planet to support life as we know it. There are some extreme cases where a planet may have other factors, such as a thick atmosphere, that allow for the presence of liquid water outside of the habitable zone.
Scientists use various models and calculations to determine the habitable zone for a star. This includes factors such as the star's luminosity, the planet's atmospheric composition, and the potential for a planet to have a stable climate. Additionally, data from telescopes and space missions help to refine our understanding of habitable zones around different types of stars.