What would be an easier way to start terraforming Mars than evaporizing the CO$_2$ deposit near the south pole ?

An autonomous nuclear heating device of about 1000 kg for instance, that landed on that deposit could penetrate it by melting first the water ice coverage and then advance somehow within the evaporating or melting CO$_2$ ice.
According to this article the top water ice layer could be up to 20 meters thick while the underlying CO$_2$ layer would count 300 meters.
If CO$_2$ gas could be produced in this layer, that could even blast away parts of the water ice layer if it is thin enough, uncovering CO$_2$ ice that would sublimate automatically.

Could there be a known way for the heating device to advance in the CO$_2$ deposit ?
For instance, could liquid CO$_2$ be used as a propellant to move the nuclear device somehow ?

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    $\begingroup$ Wouldn't it be better just to sit near the bottom of the water ice layer, melting that and letting the liquid water carry heat down to vaporize the CO2 $\endgroup$ – Steve Linton Sep 19 '18 at 9:11
  • $\begingroup$ @SteveLinton Good idea, but after all the water would have sunken down there would be still a lot of CO2 ice. Could all that ice not vaporize in the southern summer like much of the CO2 ice at the south pole does each year ? $\endgroup$ – Cornelisinspace Sep 19 '18 at 10:15
  • $\begingroup$ I assume the CO2 would vaporize over a few Martian summers if it was not covered in a cap of water ice, so removing the water ice is probably all that's needed. $\endgroup$ – Steve Linton Sep 19 '18 at 10:40
  • $\begingroup$ @SteveLinton That would be great. But i think the liquid water at the bottom of the water ice layer would turn into ice again as soon as it comes into contact with the CO2 ice, evaporizing some of it. So the water ice would stay above the CO2 ice, with CO2 gas bubbles within ? $\endgroup$ – Cornelisinspace Sep 19 '18 at 11:12
  • $\begingroup$ My first thought are it might be possible to adapt in situ leaching & hydraulic fracturing (with horizontal drilling). Drill the holes & then pump hole water into them to dissolve the CO2. The extraction wells would have a device on them that separates the water from the gas (CO2). Such technology is used in the oil & gas industry. Prior to one series of wells being depleted another set is developed. A central heating source can handle that with pipes, with the heater moved via dozer tracks $\endgroup$ – Fred Sep 19 '18 at 14:45

A nuclear heating device with a mass of around 1000kg wouldn't make a measurable difference on the martian atmosphere in it's total (nuclear) lifetime. If you use MMRTG's, the same power source that the Curiosity rover and the Voyager probes have, you could bring around 20 of them as they mass around 50 kg a piece.

Your average MMRTG puts out 125 Watts of Electrical power and 2kW of Thermal power. If we use the total power, and use the electrical power to heat, of all 20 MMRTG's, that's a thermal power output of 42.5 kW. Now 42.5 kW of heating power sounds like a lot but it really isn't on a planetary scale.

On Mars, sunlight strikes the surface with an energy of around 500 W/sqm. If mars were 100% sunlight absorbent it would require around 85 square meters of sunlight to equate 42.5 kW of power. Since it isn't, lets say we need around 200 square meters of sunlight heating to equate the nuclear heating--that's only a ~14 meter square patch of Martian soil. This means a small landslide uncovering darker sand has a larger effect on the climate than a small heater melting some CO$_2$.

If you really want to start terraforming with 1000kg, it would be more effective to bring a lot of black paint to increase heat absorbance or use your 1000kg as a small nuclear warhead.

  • $\begingroup$ Thank you for the answer but it answers not my question ! $\endgroup$ – Cornelisinspace Sep 19 '18 at 19:09
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    $\begingroup$ @Conelisinspace it seems to answer your question, because your question wasn't very specific, you start with the phrase: "What would be an easier way to start terraforming Mars than evaporizing the CO2 deposit near the south pole?" which this question does a very good job answering. 1000kg of black paint on the sand is better than 1000kg of RTGs in CO2. $\endgroup$ – Magic Octopus Urn Sep 20 '18 at 16:42
  • $\begingroup$ @MagicOctopusUrn The main question is about the way the nuclear heating device could move in the deposit The second question in the text was just an introduction to the CO$_2$ deposit. I also ended the text with 2 questions about the moving of the heating device. Why ignoring this ? $\endgroup$ – Cornelisinspace Sep 20 '18 at 19:26
  • $\begingroup$ @MagicOctopusUrn I thought of the device heated by uranium. The black paint is a really good idea, but not directly on the water ice, but on a synthetic layer with pores to let the ice evaporate. Or could graphite be a good alternative ? $\endgroup$ – Cornelisinspace Sep 20 '18 at 21:43
  • $\begingroup$ @MagicOctopusUrn Heating the CO2 deposit would lead to higher pressure of the atmosphere globally, heating the soil will only have a local effect. $\endgroup$ – Cornelisinspace Sep 21 '18 at 9:10

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