Seeding a planet with life

[Mr Monkeybat]

If after somehow mastering interstellar travel, we came across planets that are like Earth with liquid oceans of water but devoid of life. How long do you think it would take after spreading some algae and plants for its atmosphere to become breathable for humans and other Earth animals. Wouldn't such a planet be much easier to colonize than a world with its own life forms.

[fiveworlds]

Ocean's of water does not necessarily mean our plants will survive there. For all you know the soil could be very different and inhospitable to our plant growth. Temperature and light is also a factor plants on this planet are accustomed to certain ranges which may prohibit growth on other planets. Other factors include the composition of the atmosphere most plants here use oxygen and carbon dioxide along with a number of other gases in certain percentages. Now we are lucky because we know we can create carbon dioxide through the burning of fossil fuels such as coal, oil, gas etc provided these are also plentiful on the planet. We can then make oxygen from the carbon dioxide that we produce through industry. We also don't know what the effect of much higher gravity could be. I think we know plants will grow in less gravity i.e. outer space.

Edited August 9, 2015 by fiveworlds

[MigL]

Gases like methane/ethane may be there, and are considered 'fossil' fuels, but I doubt very much you'd find oil and coal on a planet that's never supported life.

[Robittybob1]

If after somehow mastering interstellar travel, we came across planets that are like Earth with liquid oceans of water but devoid of life. How long do you think it would take after spreading some algae and plants for its atmosphere to become breathable for humans and other Earth animals. Wouldn't such a planet be much easier to colonize than a world with its own life forms.

It could be a process that take billions of years to alter a planet.

Any organism is going to need more than just water to multiply even if the energy part is provided via photosynthesis.

[taovps15]

according to my way of thinking, want one planet has life

_ Firstly requires gravity, gravity to the water molecules, gas molecules are not thrown out into space

_ Two conditions in which water is life, and environmental factors such as the catalyst for living organic matter

_ 3 are necessary elements of microbial life

_ 4 need oxygen to survive life

_ 5 to the sun and light

_6 Should have ph suitable environment for organisms nontoxic development

[tantalus]

Assuming a great many things, one certain way is the way it actually did happen on earth (anaerobic cyanobacteria), and without needing to wait for evolution you could speed it up a little. Your certainly looking at tens of millions of years this way.

 

https://en.wikipedia.org/wiki/Great_Oxygenation_Event

[MEC1960]

If we should come upon an earth-like planet with liquid water it is highly probable we would not need to seed it at all - life would likely already exist there. If we happen upon the planet shortly after its formation and the appearance of liquid water (in the small window of time before life arose) and we wanted to seed it, I would not wait around to enjoy it. Unless conditions were just-so (water, atmospheric and geological conditions optimal for life) I think it would be hundreds of millions of years before the planet would be suitable for us.

[Moontanman]

If after somehow mastering interstellar travel, we came across planets that are like Earth with liquid oceans of water but devoid of life. How long do you think it would take after spreading some algae and plants for its atmosphere to become breathable for humans and other Earth animals. Wouldn't such a planet be much easier to colonize than a world with its own life forms.

 

 

If you seeded such a planet with cyano-bacteria you might eventually get an oxygen atmosphere but I can see some problems with this route. the algae could very well pollute the air with too much oxygen, I see no reason to think that oxygen levels would stop at a point that would be good for us.

 

And as has already been said it would take geologic time to change a planet in that manner and i agree that such a planet would probably already have life..

[Anthony Morris]

If after somehow mastering interstellar travel, we came across planets that are like Earth with liquid oceans of water but devoid of life. How long do you think it would take after spreading some algae and plants for its atmosphere to become breathable for humans and other Earth animals. Wouldn't such a planet be much easier to colonize than a world with its own life forms.

 

I think it would be faster to start with a planet that has microbial life already and simply colonize it with more developed life forms from Earth and possibly Europa or Mars if they have any. The process of making a world livable from scratch is just too long. I would not object to injecting life onto any empty world but I just wouldn't wait for it to get around to my level of comfort. Artificial habitats would be quicker and more certain.

 

Not all worlds with life on them would be good bets for colonization either. All life on Earth has a left-handed chirality which would make us incompatible ecologically with life forms that had a right-handed chirality. Many left-handed molecules will not interact normally with right-handed molecules and vice versa. If we ate a melon that was based on right-handed chemistry, we would gain almost no nutrition from it beyond the water and a few of the symmetrical molecules it might possess.

[CharonY]

 

 

If you seeded such a planet with cyano-bacteria you might eventually get an oxygen atmosphere but I can see some problems with this route. the algae could very well pollute the air with too much oxygen, I see no reason to think that oxygen levels would stop at a point that would be good for us.

 

And as has already been said it would take geologic time to change a planet in that manner and i agree that such a planet would probably already have life..

 

Also, there would be a need for nitrogen and carbon sources. I.e. one would need to consider atmospheric composition.

[zapatos]

If we should come upon an earth-like planet with liquid water it is highly probable we would not need to seed it at all - life would likely already exist there. If we happen upon the planet shortly after its formation and the appearance of liquid water (in the small window of time before life arose) and we wanted to seed it, I would not wait around to enjoy it. Unless conditions were just-so (water, atmospheric and geological conditions optimal for life) I think it would be hundreds of millions of years before the planet would be suitable for us.

 

While it is possible that an 'earth-like planet' is all that is needed for life to begin, I don't believe there is any data to support your assertion that an earth-like planet has a high probability of producing life. As far as we know, life only began once on earth, and an untimely rock tumbling down a hill may have put an end to that before it ever had a chance to go anywhere.

[Geert]

from: http://www.geert.com/venus.htm

 

But it would take a long, long time...

 

I explored this possibility as a student (many years ago) and recently I heard that the NASA was now studying the possibility of life on Venus along the same lines.

 

 

Injecting life into the Venusian atmosphere

 

As it never rains on Venus and atmospheric turbulence is intense, it is reasonable to assume that airborne dust particles could remain airborne indefinitely. There are organisms on earth that can survive and even thrive in the chemical and temperature conditions of Venus's upper atmosphere. Admittedly, they would have to be genetically modified and/or undergo selective breeding to do the same while remaining airborne, but this should not be such a problem as their basic design is that of a dust particle that has developed special mechanisms for clinging onto a surface. On earth this is essential as the rain makes sustained airborne life impossible. But on Venus the reverse is true and getting an organism to lose a trick is mostly not such a problem.

 

Any space probe going through the atmosphere of Venus would merely have to open a little canister with the organisms into the atmosphere. The total amount of organism released would not have to exceed one gram. Because of this low weight, a program to bring life to Venus could piggyback on an other program to Venus and could thus be very cheap indeed.

 

The idea that I am presenting here is one that have had since I was a student. I did a little feasibility study while I was studying and talked to some professors of the appropriate scientific disciplines. It proved to be a very interesting idea though lack of time and recourses prevented any future research to take place. Personally I am convinced that a determined program could successfully develop such an organism for a relatively low cost.

 

drs. Geert Poelman

Edited March 10, 2016 by Geert