Using a planet killer (Comet) to terraform Mars

PhotonBytes · 2025-01-28 18:46:39

For some reason I thought I already posted this topic and was surprised to find out I didnt. Maybe I did in a previous topic not about this so I'll create a fresh one now.

The idea here is to slow down a comet at Aphelion where it's the slowest by nuking it's surface with H bombs at it's bow the side where the comet is moving forward. This will vaporize the ice into steam and the steam will act as propellant to slow down the comet. For Halley's comet for example the Aphelion is 900m/s (0.9km/s) while it's perihelion is roughly 70km/s. By slowning down or speeding up a comet at aphelion where it's slowest you can alter the eccentricity of it's orbit and cause it to crash on a planet (sort of like a butterfly effect where small nudges cause big changes but not randomly). By causing a comet into the ice pole of Mars you can therefore liberate all that ice cap into restored atmosphere. We only need to do this for one of the Martian poles to restore preassure to Mars to roughly 0.8 bars. This is well within the Armstrong limit.

Why comet instead of Asteroids?
1) Comets have the potential and kinetic energy due to it's high orbit.
2) They have highly eliptical orbit allowing us to redirect at Aphelion
3) They have ice that act as propellant for our nukes providing thrust when H bombs are detonated.
4) Comets being comprised of ice (assuming on the out layers) allow for the possibility of nuking a nozzle to increase thrust effeciencies for subsequent ice varporizations.

Ideally we want Uranium taper Tzar bombs that have 100Megaton. With a dozen of these we can today cause Halleys comet to crash into Mercury if we wish. But for Mars Halley's is a bad candidate because the delta V would be 5km/s for Mars while under 0.9km/s for Mercury. There has already been a comet that almost hit Mars and NASA studied it's tail interacting with the planet. It could have been nudged slightly to hit the pole of the planet.

Here are the details:
https://photonbytes.com/2023/01/08/micr … r-on-mars/

DALL%C2%B7E-2024-01-17-02.38.33-A-comet-striking-the-North-Pole-of-Mars-capturing-the-moment-of-impact.-The-image-showcases-a-dramatic-and-fiery-collision-with-the-comet-ablaze-in--768x439.png

DALL%C2%B7E-2024-12-07-22.54.46-A-highly-detailed-depiction-of-a-large-comet-in-deep-space-with-a-transparent-plasma-like-spherical-nuclear-explosion-occurring-nearby.-The-comet-has.png

Altering orbital trajectory:

Artificial Nozzle Created by previous bombardments increasing efficiency for subsquent nuclear ice vaporization thrusts.

Tsar_Bomba_Revised_User-Croquant-with-modifications-by-User-Hex-Own-work-CC-BY-SA-3.0-via-Wikimedia-Commons.jpg
DALL%C2%B7E-2024-12-07-23.20.05-A-dramatic-depiction-of-the-north-pole-of-Mars-after-being-struck-by-a-comet.-The-impact-crater-is-glowing-with-intense-heat-releasing-massive-plumes.png
DALL%C2%B7E-2024-12-07-23.20.13-A-dramatic-scene-of-the-north-pole-of-Mars-after-being-struck-by-a-comet.-The-impact-crater-glows-intensely-releasing-massive-plumes-of-vapor-gas-a.png
DALL%C2%B7E-2024-12-07-23.25.26-A-stunning-depiction-of-Mars-with-its-surface-now-covered-in-vast-oceans-and-lakes.-The-once-dry-and-red-orange-Martian-landscape-is-transformed-into-.png

Last edited by PhotonBytes (2025-02-02 00:16:14)

tahanson43206 · 2025-01-28 19:32:44

The title of this new topic is generic enough to permit consideration of a non-violent use of the materials from one or more comets to gently terraform Mars over an extended period of time.

This post is reserved for an index to posts that may be contributed by NewMars members over time.

When the Solar System was younger there were lots of violent collisions, but now we have the opportunity to work with the Universe to build environments that are beneficial to humans and other Earth-life.

We have plenty of energy available from the Sun. We are using only a tiny bit of the outpouring of energy.

We humans are ** still ** living off the yolk of the egg that the Universe provided, but at least a few humans are thinking about how to wean ourselves off the store that we've inherited.

If we humans have the power to move a comet, let's just quietly disassemble it and use the materials in a gradual, controlled manner.

(th)

PhotonBytes · 2025-02-23 03:07:30

I have integrated the process of decelerating Halley's comet to hit Mercury, Venus or the Sun. Mars is not a good target for Halley's.The idea of these calculations proves that man can use comets to hit planets deliberately

Email to NASA's NIAC Ron Turner:
"Below is a conversation I had with AI about self scalping nozzle that you might be interested in because comets being made of ice means that we can create our own nozzles to increase detonation coupling efficiency. I had a deeper look at the related papers for PI defence, it looks like it could work even better if they were on a stratospheric platform that way they wont get destroyed by the incoming comet on Mars if they are thousands of km away from ground zero at a high altitude say 10km. In fact this system if done the same way on Earth on floating airships will give them higher efficiency as they are launched above the troposphere and have clearer line of sight to the target with sensors not occluded by clouds."

ChatGBT:

Me:
I was thinking that each dotonation would leave a crater and then a crater within a crater and eventually we end up with a practical nozzle so that we can eventually get close to 80% coupling

AI:
Reasoned for a second
That’s a concept sometimes referred to as a “self-sculpting nozzle.” With each successive detonation, a crater deepens and takes on a more “bell-shaped” or “nozzle-like” profile. This shape can, in theory, capture more of the bomb’s energy and direct it into vaporizing cometary material, thereby increasing the coupling efficiency.
How It Might Work
Initial Detonations:
The first few blasts are not very efficient, as a large fraction of energy escapes into space.
However, each explosion excavates a crater, exposing fresh surface area and potentially creating walls that reflect or contain a portion of the blast.
Progressive Shaping:
As the crater gets deeper and narrower, later explosions occur in a sort of “cavity.”
This geometry acts like a convergent or bell nozzle, helping to direct more of the expanding gases and energy back onto the comet’s surface rather than letting them radiate away spherically.
Higher Coupling:
With a more focused geometry, you can approach higher fractions of energy coupling—some studies speculate up to 80%—because the energy is partially contained and directed into the comet.
The repeated blasts effectively reduce losses to open space.
Challenges to Consider
Structural Stability: There’s a risk of shattering or fragmenting the comet if the blasts become too powerful or the crater becomes unstable.
Precise Placement: Each detonation must be positioned carefully so it doesn’t just punch a hole out the opposite side, losing the chance to build a self-enclosed cavity.
Material Properties: If the comet is extremely porous or loosely bound, it may not form neat crater walls; the material could just slump in or break apart.
Feasibility
While theoretically plausible, the “self-sculpting nozzle” approach is complex. In practice, engineers would have to carefully tune:
Bomb yields,
Placement depths,
Timing between detonations,
to incrementally shape the crater without destroying the comet. But as a thought experiment, it’s a fascinating way to push coupling efficiency beyond the simpler estimates of 30–50%.

For Halley's comet you need a different comet with a different trajectory.

To prevent the strike on Mars from becoming too violent it can be pulverised using this method of desteroying near Earth Asteroids
https://www.nasa.gov/general/pi-planetary-defense/

tahanson43206 wrote:

The title of this new topic is generic enough to permit consideration of a non-violent use of the materials from one or more comets to gently terraform Mars over an extended period of time.
This post is reserved for an index to posts that may be contributed by NewMars members over time.
When the Solar System was younger there were lots of violent collisions, but now we have the opportunity to work with the Universe to build environments that are beneficial to humans and other Earth-life.
We have plenty of energy available from the Sun. We are using only a tiny bit of the outpouring of energy.
We humans are ** still ** living off the yolk of the egg that the Universe provided, but at least a few humans are thinking about how to wean ourselves off the store that we've inherited.
If we humans have the power to move a comet, let's just quietly disassemble it and use the materials in a gradual, controlled manner.
(th)

Last edited by PhotonBytes (2025-02-23 03:22:53)

Calliban · 2025-02-23 11:43:36

That is a neat idea. In addition to the volatiles delivered by the impactor, the rocks beneath the impact site will be hot for millenia to come. This could be a useful source of power on either Mars or Mercury. Although Mercury is close to the sun, the long night is a problem for power supply. Having a stored heat source would help a lot.

PhotonBytes · 2025-02-23 23:10:28

So we will now not need preassure suits nor jumpers! Just a scuba tank and regulator for the oxygen while photosynthesis does its thing when we plant trees and algae in liquid water lakes.

Calliban wrote:

That is a neat idea. In addition to the volatiles delivered by the impactor, the rocks beneath the impact site will be hot for millenia to come. This could be a useful source of power on either Mars or Mercury. Although Mercury is close to the sun, the long night is a problem for power supply. Having a stored heat source would help a lot.

Last edited by PhotonBytes (2025-02-23 23:10:44)

PhotonBytes · 2025-07-19 12:27:15

There's been like 3 interstella comets coming into our solar system, I think their all comets and one of them will make a very close pass at Mars. Would be a great candidate to deflect to hit it so we can warm up the planet and melt the ice caps:
https://www.linkedin.com/posts/david-on … UpfNYm6kns
https://edition.cnn.com/2025/07/03/scie … t-3i-atlas

Last edited by PhotonBytes (2025-07-19 12:27:48)

Calliban · 2025-07-20 16:20:41

I think this is an interesting idea. The way to maximise the effectiveness of a nuclear device in changing the velocity of the comet, would be to drill a hole and bury it beneath the crust. The bomb would vaporise a lot of ice, turning it into steam which would then blast lumps of ice into space as reaction mass. The main body of the comet will then be deflected, assuming it doesn't disintegrate.

The problem is that it will be difficult to deflect the course of the comet accurately enough to hit Mars of any other body. The problem is comparable to hitting a pinhead with another pinhead across the length of a football pitch. We could use other nukes to trim its course, but each one would risk fissioning the comet.

A similar option that I looked at a couple of years back, involved placing mass drivers on Ceres or a similar icy asteroid. These would fire small water ice payloads at a velocity that would result in their perogee crossing the Martian orbit. They would explode in the upper atmosphere of Mars filling it with greenhouse inducing water vapour. The problem with doing this is similar to deflecting a comet. The mass driver would need to be extremely accurate to ensure that the majority of payloads reached the Martian atmosphere.

In short, deflecting comets and icy asteroids into Mars is a great idea, if we can do it.

Last edited by Calliban (2025-07-20 16:31:00)

PhotonBytes · 2025-07-21 07:02:38

If it were me I would send an AI controlled ship to the comet with many Tzar bombs each with it's THAAD like propulsion system which is very accurate:
https://www.youtube.com/watch?v=KBMU6l6GsdM

With AI the ship near the comet makes independent decisions without lag of Earth to comet communications. Then it fires the nukes like flying torpedoes in formation like in the scene with the sphere:

https://www.youtube.com/watch?v=n6oZTq_KsXc

Multiple blasts that trigger simultaneously at various strategic spots. The AI will also model the comet body using sensors to figure out composition of mass the best it can. It will model rotation, mass, composition, orientation, velocity, acceleration etc etc then calculate a strategy to move it to the desired trajectory and create firing solutions. After the detonations it will then repeat above process iteratively.

Last edited by PhotonBytes (2025-07-21 08:32:40)

PhotonBytes · 2025-07-24 10:15:20

Forgot to add, the incentive of smacking a comet into Mars is to melt the martian ice caps by warming up the planet with the impact preferably closer to the poles not so much deposit comet ice although that helps slightly too. Comets are better choice than asteroids because they can be moved easily by vaporization of the ice to move it while in space as you correctly pointed out and they tend to have more speed and less mas making them easier to deflect slightly especially at aphelion and contain a great deal more kinetic energy vs slower heavier asteroids. This makes them more attractive as a kinetic bomb to warm up the planet vs a carrier of ice to deposit which is only a tiny percentage of the ice caps it can melt by warming up the planet. Ice can warm up a planet if it hits it hard enough, I know counter intuitive isn't it?

Last edited by PhotonBytes (2025-07-24 10:55:22)

Calliban · 2025-07-24 13:29:40

I think the problem is that most cometary bodies are piles of loosely compacted snow and dust. The shock of a thermonuclear blast could fragment it. A fission based rocket that can alter the orbit over many decades might work better. The surface ices could be used as propellant.

If we take Halley's comet as an example. Its mass is 2.2E14 kg. To change its velocity by 100m/s, we need to impart 1.1E18J of kinetic energy. Assuming a 30% efficiency of conversion of thermal energy into kinetic energy, a total of 3.7E18 of thermal energy is needed. That is 117GW-years of nuclear heat. That is 10GW for 11.7 years.

It is doable from a logistic viewpoint. But that reactor would need to be taken all the way out to the inner Oort cloud. A long term project lasting a couple of centuries. If the goal is to continuously inject heat above the polar cap, then we need multiple comets. Maybe the Vera Rubin telescope can help identify candidates. The neat thing about getting a comet from the Oort cloud is that the energy multiplier is huge. For a 100m/s velocity change, we get an intercept velocity of over 60km/s. In terms of net energy return that is a total gain of 360,000:1. Pretty good. Directly nuking the caps would be a waste of fissile material if we can use the same energy input to get a 360,000x greater energy on target.

Last edited by Calliban (2025-07-24 14:01:21)

Calliban · 2025-07-25 02:37:42

Redirecting Hill's Cloud bodies could potentially provide a valuable energy source for future humans. If we can redirect comets to crash into planets, moons or large asteroids at a velocity of 60km/s, the cometary material will have a kinetic energy of 1.8GJ/kg at impact. Much of this energy will be captured as heat beneath the impact crater. A colony established atop such an impact crater would have access to a valuable source of geothermal heat.

This method also provides a potential method for interstellar travel. We target an icy asteroid or small moon with a comet. The impact adds kinetic energy to the body, shifting its orbit. We then use a Jupiter gravity assist to eject it from the solar system. A human colony established on the body (post impact) would be able to ride the object as a sort of slow boat to the stars. The colony would start as a relatively group equipped with a fusion reactor. Over the course of the journey, population would grow into many millions and the colonists would aquaform the body into a defacto travelling world.

Last edited by Calliban (2025-07-25 02:44:20)

PhotonBytes · 2025-07-25 04:34:05

I came up with this idea because I realized that we could push the comet significantly in just a few days with a practical number of tzar bombs at aphelion where the comet is only 900m/s and 100m/s (a doable delta v with tzar bombs) is as a result of this a relatively a large delta v at this point( equating to 1/9th velocity of comet ) that would be able to change the path of the comet significantly in a multiplier effect. This is a Hoffman orbital transfer where you time your deceleration or acceleration at the slowest and highest point in orbit where you get the biggest bang for your buck in thrusting: it's efficient. But the catch is you will have a relatively short window in time to act. This is why I prefer H bombs as they have the highest energy density and thrust compared to fission reactors containing heavy machinery designed to for a prolonged thrust with heavy fuel rods. Turns out also comets tend to have highly elliptical orbits thus making them the slowest objects in our solar system at that point in their orbits: thus working to our advantage on top of the fact they contain vaporizable ice that we can use as propellant. With fission reactors decades just won't cut it at aphelion as aphelion in this case lasts days not even a year. It defeats the idea of this space/math hack.

The lose gravel is a concern if they divide up the core of the comet. That's why firing in volleys with synchronous detonation will be favourable to mitigate this by pushing the body evenly by covering an entire face with simultaneous detonations. It's not full proof, we might still end up spreading material into a tail typical of it when its closer to the sun but it will still be a partial success if at least 19% of the material hits Mars at 70km/s.

Problem with your decades long idea is isp, it's too low. I looked into it. Besides, I rather do this in days than years. Also doesn't take advantage of the elliptical nature of the orbits, it's better for objects with circular objects or are much lighter. So I'm already skeptical. Also keep in mind that H bombs contain a lot more energy than uranium/plutonium per unit mass regarding logistics. 2.5 tzar bombs contain the energy requirement you quoted but energy coupling will initially be low at 30-45% and as we chisel out the ice nozzle it could grow to 80% as long as it's ice and not ruble making up the core.

Bottom line: the inspiration for this idea is that we can move massive icy objects not just because they are made of vaporizable propellant but because they have highly elliptical orbits making them movable within the realm of human tech at aphelion in a window of a few days. There is a multiplier effect at aphelion where comets are close to stationary: that amplifies tiny changes there all the way down as big changes to perihelion. The payoff being that at perihelion we have the opposite condition being true that is a super fast 70km/s comet that can deposit vast quantities of heat energy to a planet to melt it's ice caps such as Mars. Heck it doesn't even need to impact directly on the poles! The type of impact that killed the dinosaurs can melt the ice caps on Mars too, makes me wonder if our ice caps also melted because of the dinosaur killing comet.

To get the tech out to those aphelion is another subject but I'm optimistic because we can use the tzar bombs them selves as a kind of Orion/daedelius style ship to get the bombs there or net the comet and hitch a ride there.

Calliban wrote:

I think the problem is that most cometary bodies are piles of loosely compacted snow and dust. The shock of a thermonuclear blast could fragment it. A fission based rocket that can alter the orbit over many decades might work better. The surface ices could be used as propellant. If we take Halley's comet as an example. Its mass is 2.2E14 kg. To change its velocity by 100m/s, we need to impart 1.1E18J of kinetic energy. Assuming a 30% efficiency of conversion of thermal energy into kinetic energy, a total of 3.7E18 of thermal energy is needed. That is 117GW-years of nuclear heat. That is 10GW for 11.7 years.
It is doable from a logistic viewpoint. But that reactor would need to be taken all the way out to the inner Oort cloud. A long term project lasting a couple of centuries. If the goal is to continuously inject heat above the polar cap, then we need multiple comets. Maybe the Vera Rubin telescope can help identify candidates. The neat thing about getting a comet from the Oort cloud is that the energy multiplier is huge. For a 100m/s velocity change, we get an intercept velocity of over 60km/s. In terms of net energy return that is a total gain of 360,000:1. Pretty good. Directly nuking the caps would be a waste of fissile material if we can use the same energy input to get a 360,000x greater energy on target.

Last edited by PhotonBytes (2025-07-26 01:46:45)

PhotonBytes · 2025-07-25 12:09:36

What chatgbt thinks
https://www.linkedin.com/posts/david-on … UpfNYm6kns

In case that wasn't clear it thinks that Mars is semi geologically active so the reactivated volcanoes would help warm up the planet more and melt the ice caps!

Last edited by PhotonBytes (2025-07-25 12:52:56)

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#1 2025-01-28 18:46:39

Using a planet killer (Comet) to terraform Mars

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