Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Mars Terraforming

  1. May 30, 2008 #1
    I've always wondered if Venus, which has many similarities to the Earth, would have had an Earth like habitat if/when it was further away from the sun like the Earth is. I also don't know if or how orbits and day length are affected by distance from the sun as well. On the assumption that Mars will get closer to the sun over time, I still don't know if the sun would expire and blow up before the orbit is significantly changed.


    A reason for life on Earth is the magnetic field from molten iron in the core. A banal guess for this is simply because the Earth is the right size for gravity to create friction inside the core.

    Assuming that Mars has all the right stuff (elements) and enough time on its hands, could it be terraformed by diverting a myriad of comets and asteroids into it? Could it be terraformed by its own gravity if its mass was simply increased?
  2. jcsd
  3. May 30, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Planets actually drift slowly away from the sun due to tidal friction.
    The sun will only expand in radius in at the end of it's life - it's not continually expanding.

    Venus would have a lower temperaure if it was at Earth's distance - although it's atmosphere would still be pretty unpleasant!
    Earth's magnetic field is due toi it's size, it is big enough that the graviational energy of the original collapse melted the core and large enoughj to insulate the core and keep it molten.
    Terraforming mars is largely just a matter of adding some atmosphere - it is near enough to the sun that a high density atmosphere would warm it to 'almost' habitable tempeatures.

    The SF books Red mars/green mars/blue mars by kim stanbley robinson are excellent descriprtions of the process ( at least the first book )
  4. May 30, 2008 #3
    Thanks for the reply.

    I wasn't sure about them drifting away or not. But my main concern was how would mars get a big enough magnetic field because without it, I've heard that solar winds would wither away the atmosphere. That and if it were more massive, less atmosphere could escape.

    Again thanks for the reply.
  5. May 30, 2008 #4


    User Avatar

    Staff: Mentor

    Can you elaborate? I know tidal friction slows down rotation - that's why Moon shows us only one side, that's why day on Earth is getting longer. I suppose that's also why Mercury day is in a resonance with its year. But somehow I fail to imagine why and how it could move planets away. That'll mean accelerating the planet at the price of slowing down its rotation?

    If anything, I always thought that planets can get slowed by the friction - just like every Earth satellite on low orbit is doomed because of the thermosphere that slows it down. While we are definitely outside of the Sun atmosphere vaccum inside of the Solar system is full of dust :wink: and could have similar effect.

    See also "The Case for Mars: The Plan to Settle the Red Planet and Why We Must" by Robert Zubrin and Richard Wagner.
    Last edited: May 30, 2008
  6. May 30, 2008 #5
    A big problem is Mars lack of an http://en.wikipedia.org/wiki/Magnetosphere" [Broken] on earth it protects life from the radiation from space, which would make terraforming of Mars more difficult. But if you have a thick atmosphere then the radiation would be absorbed in the atmosphere. But another problem is that the solar winds from the sun will gradually blow off the slower atmosphere but would take thousands of years(but of course it takes thousands of year to make a planet earth-like)

    But yes it is possible. We just don't have the technology yet.
    Last edited by a moderator: May 3, 2017
  7. May 7, 2010 #6
    I woke up with the craziest of idea.

    My guess is that Mars dont have a dynamo effect in it's core. As in Earth, the iron rich part of the core rotates creating the magnetosphere we all know. I also know there is a tidal energy produced by the movement of the Moon locked with the Earth orbit. Thus gravity pulls both ways planet & moon. My guess is that what Mars need is a massive moon in a stable orbit. A moon that while moving around the planet would generate a tidal force on Mars core. My bet is that gravity is the much needed ignition for the core revival. Now, where to find a moon suited for Mars.
    That is where my dream became wackier.... Ceres.
    Ceres is about the size of Europe (the continent), thus is about the half the mass of Mars. Whlie we don't know everything about Ceres until the Horizon's project. I can guess it is a hot core, dense "dwarf planet".
    -How to pair Ceres with Mars?
    Ceres is just 2 A.U. from Earth, but in an eccentric inclination. It is just farther than Mars.
    If, & only if there a way to place rockets on Ceres and drive it toward Mars (tons of thrust & energy), then steer it just in the correct position around Mars (lots of thrust. energy, money, calculations & luck)
    This was my wacky dream.
    I'm a mechanical engineering student in sophomore yr,
    fascinated with space exploration.
    THanks for reading

    Juan Di Donna Perea
  8. May 8, 2010 #7
    I have always thought that without a strong magnetosphere it would be pointles to terraform Mars. Our magnetosphere protects use from much more of the Sun's energy than our atmosphere could ever do. Using an orbital mass to cause the core to melt never occured to me but I had thought about using fissionable materials to do it. I don't know how much it would take but it would probably be as difficult as moving Ceres into position.
  9. May 10, 2010 #8
    Even once a satellite is tidally locked, it still tugs on the surface of the body it orbits, just as the moon is tidally locked with the earth, and so the moon experiences no tides from the earth, but we on earth experience tides from the moon. This slows down the rotation rate of the body it orbits, and the resulting loss of angular momentum is transferred to the satellite, increasing angular velocity and thus the radius of it's orbit.

    At least that's how I understand it, but I may very easily be wrong.
  10. May 10, 2010 #9


    User Avatar

    Staff: Mentor

    Nice one, thanks.
  11. May 10, 2010 #10


    User Avatar
    Science Advisor

    You're right, but the effect is irrelevant at planetary scales.
    The sun's mass is constantly decreasing due to solar wind and radiation. This makes the planet's orbits grow over time.
    The habitable zone shifts also to larger orbits, because the sun gets hotter and hotter. In total, mars will get warmer than it is today.
  12. May 10, 2010 #11
    It would be possible, but as always terraforming is something we shouldn't even be considering. We should worry more about saving this planet instead of making another one more suitable for life in the future.

    Dr.Carolyn McKinney < Dr. Devin Mei
    Dr. Jack Phillips > Carolyn McKinney
    Dr. Carolyn McKinney < Dr. William Cooper
  13. May 10, 2010 #12
    One way or other, this planet will become unsuitable for life at some point in the future. Possibilities include the inevitable solar life cycle, global thermonuclear war, a superplague, asteroid or comet collision, massive extra-solar object wrecking havoc with the planetary orbits, other forms of uncontrollable climate change (we have been encased in ice at least twice in our long history).

    There is no reason for humanity to "go down with the ship" without at least trying. How do you think we got to the top of the food chain? Terraforming Mars would be a logical first step in preparing to leave the solar system. The process will be a very long one and there is no good logical reason not to start NOW.

  14. May 21, 2010 #13
    That is precisely the opposite of reality. Only a tiny fraction of the energy emitted by the sun is in the form of charged particles that can be affected by magnetic fields, and those do not penetrate far into the atmosphere. Non-solar radiation consisting of high energy particles does better, secondary radiation from collisions in the atmosphere can reach the ground...the magnetic field isn't strong enough to shield these particles, but the atmosphere still stops them. The bulk of the sun's radiation is EM, and the magnetic field does absolutely nothing against that portion...the atmosphere is fortunately fairly opaque to UV and above.
  15. May 29, 2010 #14
    "the moon experiences no tides from the earth"

    IIRC, it does, partly due to the slightly elliptical orbit. Result is mild, deep moon-quakes detected by the Apollo missions' leave-behind seismometers.
  16. May 29, 2010 #15
    Why not just start building all our factories on Mars and emit all the greenhouse gasses on the Martian atmosphere. Let global warming do the work of warming.

    For Venus grow Oxygen producing bacteria in the cloud away from the high surface temperature to reverse the high carbon dioxide and monoxide in its atmosphere. That is how the Earth became inhabitable.

  17. May 30, 2010 #16


    User Avatar

    Staff: Mentor

    The day you will find a way of moving coal and oil cheaply to the Mars we can try.
  18. May 30, 2010 #17


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Why not do both if possible? After all, it is rarely a good idea to keep all your eggs in one basket if you can avoid it.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook