Terraforming Mars obstacles

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  • #51
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Not only is the Tsar Bomba a bomb, it is a nuclear weapon. Nuclear weapons are banned from space. People protested against launching Cassini because it had a puny little RTG. What do you think the world's reaction would be regarding launching "a couple hundred Tsar Bombas" into space?
Agreement Governing the Activities of States on the Moon and Other Celestial Bodies
Article 3
3. States Parties shall not place in orbit around or other trajectory to or around the moon objects carrying nuclear weapons or any other kinds of weapons of mass destruction or place or use such weapons on or in the moon.
http://www.unoosa.org/oosa/en/SpaceLaw/gares/html/gares_34_0068.html [Broken]


Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies
Article IV
States Parties to the Treaty undertake not to place in orbit around the earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner.
http://www.unoosa.org/oosa/en/SpaceLaw/gares/html/gares_21_2222.html [Broken]
 
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  • #52
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Get real! To move Deimos,or Phobos, or some other rock, the energy has to be focused and constrained. In case you hadn't noticed, the Tsar Bomba is --get this -- a bomb. A very big bomb that releases an incredible amount of energy in an incredibly short interval of time and over four pi steradians. How are you going to direct the energy in one direction and keep the energy from blowing up the rock you want to move?
One could place the explosives in a parabolic crater, and/or use 400 or 600 tsar bomba's instead of 125 to ensure enough energy is directed in the right direction. Wasting energy blowing the moon apart instead of pushing it is an issue worth consideration, however.

Not only is the Tsar Bomba a bomb, it is a nuclear weapon. Nuclear weapons are banned from space. People protested against launching Cassini because it had a puny little RTG. What do you think the world's reaction would be regarding launching "a couple hundred Tsar Bombas" into space?
Well, thats not really a engineering problem so much as a political one.
 
  • #53
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Thank you, B. Elliot! I was afraid I was the only voice of sanity in this thread.

Maze and sanman: What exactly is your intention here? If you want to discuss near-term policy, fine. Stop the science fiction if that is the case. If, on the other hand, you want to discuss science function, that is fine too. Keep it a bit real, and don't even begin to pretend that humanity should begin moving in this direction.
 
  • #54
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I don't pretend to know what "humanity" should or should not do. It's just an interesting engineering thought experiment.
 
  • #55
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No, its not. Engineering is deeply concerned with feasibility, cost, liabilities, and practicality. This thread has degenerated into the realm of science fiction.
 
  • #56
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Exactly, since this is a discussion board, we should not be afraid to discuss.

Suppose we could use a nuclear explosion to precisely split off a sizeable chunk of Phobos or Deimos, to send that spiraling down to Mars, and hit the icecaps.

Maybe dropping a whole moon is overkill. Maybe we just need a 1000-meter diameter chunk to fall on the icecaps, and also time it for the right part of the year, for best overall weather conditions.

An expanding CO2 gas cloud in the low Martian atmospheric pressure (1% Earth atm) would expand more rapidly to cover a wider area. If we were to create one at the right time of day, right time of year, etc, perhaps we could reduce the size requirements.
 
  • #57
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This is a scientific discussion board. There are plenty of other boards out there where you can discuss pseudoscience.
 
  • #58
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Also, what about the idea of dropping some big nukes on Mars?
Perhaps something could be specifically engineered to minimize the production of fallout and residual radioactivity - not that Mars doesn't currently have high levels of radiation from space.
If you could create an atmosphere, you might improve the radiation situation overall.

The largest nuclear weapon ever detonated was a Soviet explosion in 1961, which was 50 Megatons, using a bomb that weighed 27 tons. But nobody has said this was 27 tons of fuel. I'm imagining that a lot of this was from the overall apparatus and casing, which would have been designed back in that very first decade of Soviet nuclear technology.

There were no supercomputers back then, or other modern tools to achieve the design efficiencies possible with today's technology.

I'm wondering if today it wouldn't be possible to build not just a more powerful and lighter weapon, but also to create a shaped explosion with a flatter, more lenticular shape to radiate energy horizontally more than vertically. That would cover more icecap area.
Maybe an appropriately shaped multi-stage bomb design could do that.

(Although blast radius in vertically downward direction could perhaps have the benefit of breaching the Martian crust to liberate geothermal energy. The Martian crust is also peculiarly thin in the northern polar region, at 32 km thickness. Also, creating lower depressions would afford higher atmospheric pressures and temperatures at those depths, which might be more conducive to liquid water and supporting life.)
 
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  • #59
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Stop with the nukes. It ain't gonna happen.
 
  • #60
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This is a scientific discussion board. There are plenty of other boards out there where you can discuss pseudoscience.
I think you are confusing pseudoscience with impractical science. Rough estimates have already demonstrated that it is potentially feasible, if impractical, to effect serious change in the orbit of a small moon with energies available to us. If you are not interested in this subject, I recommend you stop reading the thread.
 
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  • #61
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I think you are confusing pseudoscience with impractical science.
Due to the fact that nukes in space are outlawed by the order of international space law, it's currently impractical and will remain that way intil those laws are changed.
 
  • #62
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Overly Speculative Posts:
One of the main goals of PF is to help students learn the current status of physics as practiced by the scientific community; accordingly, Physicsforums.com strives to maintain high standards of academic integrity. There are many open questions in physics, and we welcome discussion on those subjects provided the discussion remains intellectually sound. It is against our Posting Guidelines to discuss, in most of the PF forums, new or non-mainstream theories or ideas that have not been published in professional peer-reviewed journals or are not part of current professional mainstream scientific discussion. Posts deleted under this rule will be accompanied by a private message from a Staff member, with an invitation to resubmit the post in accordance with our Independent Research Guidelines. Poorly formulated personal theories, unfounded challenges of mainstream science, and overt crackpottery will not be tolerated anywhere on the site. Linking to obviously "crank" or "crackpot" sites is prohibited.
 
  • #63
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Those rules apply to crackpot theories of the laws of physics, not strangely novel applications of correct laws of physics.

I find it hard to believe the level of hatred this thread is generating.
 
  • #64
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It is not hatred, it is frustration. The thread started on a bad footing and just got worse.

Thread reported.
 
  • #65
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Those rules apply to crackpot theories of the laws of physics, not strangely novel applications of correct laws of physics.

I find it hard to believe the level of hatred this thread is generating.
It's not hatred as I share the same dreams as you do and have had the exact same thoughts as you're having. It's just that you have to know where to draw the line with practicality.
 
  • #66
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The proposals for terraforming, particularly with thermonuclear bombs, were presumptive and didn't address some fundamental issues with respect to feasibility, particularly with respect to atmospheric retention. One must consider what is available to terraform Mars and the goal of such a program.


Mars information from http://en.wikipedia.org/wiki/Mars
The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds.

Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. Mars's axial tilt is 25.19°, which is similar to the axial tilt of the Earth. So a Martian winter would be nearly twice as long as one on earth, and perhaps much colder.

Surface temp.
min . mean . max
186 K 227 K 268 K
-87°C -46°C -5°C

So for humans to live in an environment similar to that of Earth, the max temperature of Mars would have to be increased by about 30-35°C, and ideally the minimum would increase by about 50°C, otherwise significant thermal differentials would drive extreme weather (i.e. high wind velocities). Given that Mars is 1.52 AU from the sun, it receives less than half the solar energy flux as the earth (~43%).


But one has to ask, why Mars doesn't have an atmosphere. Well, it simply doesn't have enough gravity to retain the light gases like N2, O2, and water vapor H2O. So, even if the CO2 on Mars was released and converted to O2, and the water was released as vapor, the O2 and H2O would simply escape to space, especially if the temperature were to be increased to levels experienced by Earth's atmosphere.

http://zebu.uoregon.edu/~soper/Mars/atmosphere.html [Broken]

So the gravity would have to be increased on Mars by adding mass,
but then from where would the extra mass come. Phobos? Deimos? Asteroids?

Consider the following:

Mars - mass = 6.4185×1023 kg / 0.107 Earths
Equatorial surface gravity 3.69 m/s² (0.376 g)

Phobos - mass = 1.07×1016 kg (1.8 nEarths)
Deimos - mass = 1.48×1015 kg

The masses of Phobos and Deimos are inconsequential, being less than one ten-millionth of the mass of Mars.


Well - what about the asteroids?


More than half the mass within the main belt is contained in the four largest objects: Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea. All of these have mean diameters of more than 400 km, while Ceres has a diameter of about 950 km.

From - http://en.wikipedia.org/wiki/Ceres_(dwarf_planet)#Physical_characteristics
The combined mass of the current asteroid belt is only a small fraction of the mass of the Earth's Moon - mass 7.3477×1022 kg (0.0123 Earths)

The mass of Ceres has been determined by analysis of the influence it exerts on small asteroids. The mass of Ceres comprises about a third of the estimated total 3.0 ± 0.2 ×1021 kg mass of the asteroids in the solar system, together totalling about 4% of the mass of the Moon.

Ceres - mass 9.43 ± 0.07×1020 kg, orbit semi-major axis 414,703,838 km
Kovacevic, A.; Kuzmanoski, M. (2007), "A New Determination of the Mass of (1) Ceres". Earth, Moon, and Planets 100: 117–123.
http://adsabs.harvard.edu/abs/2007EM&P..100..117K

Pitjeva, E.V. (2005), "High-Precision Ephemerides of Planets — EPM and Determination of Some Astronomical Constants," Solar System Research 39 (3): 176.
http://iau-comm4.jpl.nasa.gov/EPM2004.pdf [Broken]

4 Vesta - mass 2.7×1020 kg, orbit semi-major axis 353,268,000 km

2 Pallas - mass 2.2×1020 kg, orbit semi-major axis 414,784,000 km

10 Hygeia - mass 8.6 ± 0.7 ×1019 kg, orbit semi-major axis 469,345,000 km

http://en.wikipedia.org/wiki/Image:Moon_and_Asteroids_1_to_10.svg


Collecting all the asteroid mass in solar system, would yield about 4% (0.04) of the lunar mass, which is 11.4% (0.114) mass of Mars. So adding all the asteroid mass to Mars would increase its mass 0.04 * 0.114 = 0.00456, and that would still be insufficient to retain an atmosphere with density and temperature similar to earth. Even adding the moon with the asteroids would only increase the mass of Mars by approximately 12%, and it would still be insufficient.


What about the moons of Jupiter and Saturn? Well, they are a long way off, and one would have to lift the moons out of the gravity wells of Jupiter and Saturn.


Jupiter - orbit semi-major axis 778,547,200 km

Saturn - orbit semi-major axis 1,433,449,370 km
 
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