Terraforming, what would it take?

I noticed some thoughts about terraforming Mars after the huge discovery of water ice at the Poles. Large impactors I believe tend to cool a planet surface. I'm just wondering, if a very large impact occurred on Venus, would this expel enough of the atmosphere to cause the planet to cool off? Could we terraform Venus?

Given enough time, a large asteroid or object can be made to divert course. We could cause such an object or objects to crash into Venus and possibly terraform the planet.

However maybe this is dreaming since we might need a Mars size object to crash into Venus to have sufficient mass to dispel that much of the atmosphere. Perhaps this is exactly what happened to the Earth when the object that supposedly became our moon impacted the Earth. Any thoughts?

As an additional thought on this matter, the idea of letting algae or other known life forms grow on the surface of Venus is a bit ridiculous in my opinion as a means of cooling the planet. The surface of Venus is hot enough to melt lead. I don't know of any plants that can survive that heat. Thoughts from
www.newscientist.com...




[edit on 18-3-2007 by orionthehunter]

Venus can be seeded with algae and bacteria that can survive the conditions, and stay suspended in the atmosphere. Over time they could convert some of the CO2 into O2 and diminish the greenhouse effect that keeps the temps there so high.

Impacts from celestial bodies do not necessarily cause global cooling. It all depends on the type of impact.

Mars needs to warm up for terra forming. It also needs to have an active crust and core. Impacts of enough intensity could do that, but it would take a great deal of energy transfer for it to work.

In any case, we are a very long way away from being able to terra form any planet. Heck, we cant even manage our own biosphere very well.

I think Terraforming is one of the most interesting parts of Astronomical
science.

Mars and Venus are the best choices in our own Solar System.


From what I understand from reading on the subject, impacting Venus
would really not be the best idea, as it would just put more material into
the atmosphere, and so would not help in any way.

The best thing to do with Venus is develop special bacteria to be added
to the atmosphere and slowly diminish the greenhouse gasses in the
atmosphere.

A sun shade may also be required, as it is closer to the sun than the
Earth is.


As fro Mars, well in my opinion Mars is the better choice for out first
Terraforming project.

Mars, as has been discovered, has vast water reservoirs, as well as
CO2 in the form of dry ice.

By warming the planet, through adding CFTs to the Martian atmosphere,
the temperature would rise enough for the CO2 to start melting, and that
would in turn raise the temperature even further and start the melting
of the water ice.

By adding special algae, and other plants to Mars, we could than start
converting the atmosphere to something more breathable to Terran life.

Another thing to consider is that Mars has a very small Magnetic field,
and as such over time the atmosphere would be stripped from the planet
by solar winds,however this would take a very long time, but it would still
be something that needed to be dealt with.

An ingenious idea I remember reading about a few years back on ATS was
to tow a bunch of Iron/magnetically active asteroids into Martian orbit in
various locations to provide a Magnetic field.
Doing so would also allow for orbital habitats above Mars where the
special organisms and chemicals could be produced to be sent to the
Surface, which would significantly reduce the money required if we
were sending everything from Earth.

All in all to make Mars a livable place, from start to finish would take
between 300 and 600 years.


Anyways, those are my thoughts on it.

I thought about plant life in the atmosphere of Venus as well. The atmosphere is so dense it might be comparable to an ocean. It's the idea of plants growing on the surface of Venus I thought was ridiculous. Perhaps the reporter writing the story about the scientist got his/her story wrong. I would have thought a scientist would know that algae may not grow well at 800 degrees F. Maybe a scientist will say algae can grow at temperatures that hot and then I'll be surprised.

Talk about activating motion within Mars itself sounds pretty far fetched by anything we'll be able to achieve in the next 100 years I believe. If only we had something like Martian kudzu that could transform the planet of Mars. Of course to do that might kill any life already there and transform the planet into a jungle. It might be 2030 something before man even sets foot on Mars. Seems like terraforming could be a form of alien terrorism if someone didn't care for whatever life may already be growing there. If mankind goes to Mars to live, we'll probably be terraforming the planet bit by bit trying to get plants to grow there. Venus is too hot and the pressure would kill anyone standing on the surface unprotected.

Just read the post above. Interesting idea with using asteroids to create a magnetic field. I'm wondering how many that would take.
The other problem I saw with using asteroids or very large objects to impact Venus would be if you had a really big impact, debris could come back to Earth.


[edit on 18-3-2007 by orionthehunter]

Originally posted by orionthehunter
Just read the post above. Interesting idea with using asteroids to create a magnetic field. I'm wondering how many that would take.

Well it would depend on how powerful the magnetic field of each asteroid
is, and how much coverage it gives.

The other problem I saw with using asteroids or very large objects to impact Venus would be if you had a really big impact, debris could come back to Earth.

It may, or it may not, if an impact of something half the size of the Moon
or larger hit it, than definately yes, but a smaller one may not actually
cause material to impact the Earth, atleast within the next few thousand
years.

However though, I really don't see the point in crashing an asteroid into
Venus anyways.

Adding ferrous asteroids to an orbit around Mars would not create a proper magnetosphere. The only way for Mars to have a magnetosphere would require Mars to have a molten, ferrous core that is in rotation. An external orbiting system would not provide the proper type of field to prevent the atmosphere from being stripped away over time. We need to get the core of Mars heated up enough to melt, and hope that it is iron based. Given how we believe planetary cores form, there is a good chance that it has enough iron.

Yeah, but what in the world can we do to get it started? Multiple undergrown Gigaton Nukes? That'll prolly do it.

For mars I see 2 methods that need to be applied.

Mars has large CO2 ice bodies and large H2O ice bodies.

You'd need to start a greenhouse effect that melts all that, introduce "something" to convert a bit of CO2 into O2 (algae and bacteria sound good) and you can also use some method to get O2 out of the H2O on mars, but I wouldn't do that unless there isn't enough O2 comming out of the CO2.

Preservation of the water available on mars is needed imho.

If you end up having enough O2 in the atmosphere that its livable but have entirely no water left on mars, the planet wouldn't be all to suitable for life anymore.

For Mars terraforming, we need to send flying machines that take as input the CO2 of the atmosphere, use the Carbon to move themselves around and release the Oxygen to the atmosphere.

These machines can fly by using the helicopter principle.

By sending some 10s of thousands of these machines, Mars could be terraformed within 5 years.

Originally posted by masterp
For Mars terraforming, we need to send flying machines that take as input the CO2 of the atmosphere, use the Carbon to move themselves around and release the Oxygen to the atmosphere.

These machines can fly by using the helicopter principle.

By sending some 10s of thousands of these machines, Mars could be terraformed within 5 years.

That would not terraform the planet, you can't just turn the neglible
amounts of CO2 in the atmosphere into Oxygen, apart from that fact
that there is'nt anywhere near enough to breathe, it would not make
Mars hospitable.

The total terraformation fo Mars will take somewhere around 500 years.
If we started though, we would start seein results within 50 years.