Terraforming mars in a short time

(Parallax) wrote in
om:

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.


Owch.
Whacking that into Mars, on cometary type trajectories.
Impact at about 39km/sec
Total kinetic energy released = 1.27 * 10^24 joules
== 426 *Million* Megatons equivalent

Did you want to give Mars an atmosphere, or smash it to gravel?

Marvin wrote in message ...
(Parallax) wrote in
om:

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.


Owch.
Whacking that into Mars, on cometary type trajectories.
Impact at about 39km/sec
Total kinetic energy released = 1.27 * 10^24 joules
== 426 *Million* Megatons equivalent

That's sorta why I'd like to rip the comets apart before they impact,
so they can impact the Martian atmosphere as a stream of gas.

My simple calculation assumed the existing martian atmosphere is about
50 KM high and of constant density (not a real good model)

So, my estimate of 2600 comets should be stated more exactly as:

2600 +/- a bunch.

Did you want to give Mars an atmosphere, or smash it to gravel?

"Marvin" wrote in message
...
(Parallax) wrote in
om:

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.


Owch.
Whacking that into Mars, on cometary type trajectories.
Impact at about 39km/sec
Total kinetic energy released = 1.27 * 10^24 joules
== 426 *Million* Megatons equivalent

Did you want to give Mars an atmosphere, or smash it to gravel?

I would like to see the numbers on this 2600 comets at 20 km diameter
only raising the pressure to .1 of Earth. I estimate 2 atm pressure from the
same material, also not figuring greenhouse and impact release.

"Aozotorp" wrote in message
...
much snipped
Really??? And you have the Physics of that worked out???

I personally haven't worked out the physics but Martyn Fogg, a very smart
gentleman who has written a very impressive book on terraforming, calculated
the figures that I mentioned i.e. that Mars has CO2 reserves for a 2 Earth
Atmosphere equivalent atmosphere and that it will persist for at least 10s
of millions of years once released.

Robert Zubrin, who is one of the foremost proponents of the nearterm manned
exploration of Mars, derived very similar figures.

Scientists at NASA have similar ideas.

Sci.space.tech's Henry Spencer who is very seldom wrong about anything will
give you a very similar set of numbers and probably a list reference as
where he bases his ideas. Geoffrey Landis (whom I haven't seen posting for a
while - are you about Geoffrey?) is also very seldom wrong and will give you
a similar set of numbers.

You don't have to go smashing comets into Mars to terraform it. You just to
need to add enough heat to get the CO2 out of the poles and the rocks that
it currently resides in. What you do with it afterwards is up to you. It is
a lot of CO2.

Mars will remain nitrogen poor. You might want to ship in some comets for
that. But you might want to find some alternative way of landing them other
than lithobraking. Lithobraking messes up the landscape in unprecedented
sorts of ways.

Regards
Frank

Parallax wrote:
(Aozotorp) wrote in message ...

"Aozotorp" wrote in message
...

The more you heat Mars, the more atmospheret will boil off into space!

A Martian atmosphere of two Earth equivalent surface pressures would be
stable for a geological time period. Like 10 million years. Long enough for
humanity to set up home, complete terraforming, nuke ourselves back into the
stone age, redevelop technology, colonize the solar system, evolving into a
higher lifeform, move onto the Oort, develop FTL and head off to
Andromeadia. Boil-off into space is irrelevant unless you're talking about a
much more lumiscant sun and 5-billion year time periods.

Regards
Frank Scrooby


Really??? And you have the Physics of that worked out???

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.

You know that H2O is a potent greenhouse gas? That would create one
hell of a steamy Mars...

--
Sander

+++ Out of cheese error +++

Marvin wrote:
(Parallax) wrote in
om:

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.


Owch.
Whacking that into Mars, on cometary type trajectories.
Impact at about 39km/sec
Total kinetic energy released = 1.27 * 10^24 joules
== 426 *Million* Megatons equivalent

Did you want to give Mars an atmosphere, or smash it to gravel?

He just wanted to restart vulcanism :P

--
Sander

+++ Out of cheese error +++

"Frank Scrooby" wrote in message ...
"Aozotorp" wrote in message
...
much snipped
Really??? And you have the Physics of that worked out???

I personally haven't worked out the physics but Martyn Fogg, a very smart
gentleman who has written a very impressive book on terraforming, calculated
the figures that I mentioned i.e. that Mars has CO2 reserves for a 2 Earth
Atmosphere equivalent atmosphere and that it will persist for at least 10s
of millions of years once released.

Robert Zubrin, who is one of the foremost proponents of the nearterm manned
exploration of Mars, derived very similar figures.

Scientists at NASA have similar ideas.

Sci.space.tech's Henry Spencer who is very seldom wrong about anything will
give you a very similar set of numbers and probably a list reference as
where he bases his ideas. Geoffrey Landis (whom I haven't seen posting for a
while - are you about Geoffrey?) is also very seldom wrong and will give you
a similar set of numbers.

You don't have to go smashing comets into Mars to terraform it. You just to
need to add enough heat to get the CO2 out of the poles and the rocks that
it currently resides in. What you do with it afterwards is up to you. It is
a lot of CO2.

Mars will remain nitrogen poor. You might want to ship in some comets for
that. But you might want to find some alternative way of landing them other
than lithobraking. Lithobraking messes up the landscape in unprecedented
sorts of ways.

Regards
Frank

I decided to use comets because the energy requirement to heat the
Martian CO2 to produce an atmosphere might be unreasonable while the
kinetic energy of a comet is there for free. Furthermore, comets seem
to have some nitrogen in them (Methyl Cyanide).

For my very rough calculation, I used the minimum density for Comet
Encke of .16 gm/cm3 I found on the web and arbitrarily decided that .2
was better. I read in National Geographic (It came yesterday) that
Mars surface atmosphere is about 1% density of earths which I once
calculated at about .016 gm/cm3 (once again, could easily be wrong and
based on my poor memory). Picked an atmospheric height of 50 Km for a
fictitious atmosphere based on something I read about the heatshield
on Spirit and decided the simplest model was uniform density with
height cuz this would overestimate the number of comets, calculaated
this atmospheric volume and got this number. My intention was to
decide if the correect number of comets was "just a few" comets or
"gazillions".

Now, to avoid too much damage from comet impact, perhaps we could
spread the impact over the total surface of Mars (actually its
atmosphere) by "expanding" the comet as it approaches Mars. So, as it
gets closer in toward the sun, we nuke its interior to make many
fissures and then allow warming by the sun to heat it. This cause it
to have a big "coma" and big tail which follow the comet to its demise
on Mars.

I do not pretend to know if any of this is remotely correct (except
the x-ray heating stuff) and will leave any details to the experts
(hey, its just an engineering problem).

In article , Frank Scrooby wrote:
I personally haven't worked out the physics but Martyn Fogg, a very smart
gentleman who has written a very impressive book on terraforming, calculated
the figures that I mentioned i.e. that Mars has CO2 reserves for a 2 Earth
Atmosphere equivalent atmosphere...

Careful here. Nobody is *sure* of that. Martyn Fogg is a sharp guy, but
such calculations inevitably rest on assumptions which are not much better
than guesses right now.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |

Marvin wrote in message ...
(Parallax) wrote in
om:

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.


Owch.
Whacking that into Mars, on cometary type trajectories.
Impact at about 39km/sec
Total kinetic energy released = 1.27 * 10^24 joules
== 426 *Million* Megatons equivalent

Did you want to give Mars an atmosphere, or smash it to gravel?

It's not that bad. First, you're pretty much assuming the comet is
coming in from the side. You can reduce the energy release by having
your comets approach in the same direction that Mars orbits though
that might restrict your choice (some comets would have a bad
configuration, eg, retrogade orbit).

Second, that amount of energy is equivalent to that released by a full
blown huricane over 70 years. It's a lot of juice, but IMHO well
within range of what can be dissipated by weather systems (and thus
heat radiation from a planet) over a few years. I'd be far more
concerned about losing atmosphere to the initial impact (the rebound
could knock a lot of the incoming material and atmosphere off the
planet), and dirtying the near-Mars environment with a lot of debris.

Other posters have mentioned the main solutions. Break up the material
so that it has a larger impact area, and decelleration.


Karl Hallowell

Sander Vesik wrote in message ...
Parallax wrote:
(Aozotorp) wrote in message ...

"Aozotorp" wrote in message
...

The more you heat Mars, the more atmospheret will boil off into space!

A Martian atmosphere of two Earth equivalent surface pressures would be
stable for a geological time period. Like 10 million years. Long enough for
humanity to set up home, complete terraforming, nuke ourselves back into the
stone age, redevelop technology, colonize the solar system, evolving into a
higher lifeform, move onto the Oort, develop FTL and head off to
Andromeadia. Boil-off into space is irrelevant unless you're talking about a
much more lumiscant sun and 5-billion year time periods.

Regards
Frank Scrooby


Really??? And you have the Physics of that worked out???

A "side of the envelope calculation" (even more cursory than back of
the envelope), gives about 2600 comets each about 20 Km diameter to
raise the atmospheric pressure from .01 earth to .1 earth. This uses
only the material of the comet (assumed .2 gm/cm3) and does not
account for any greenhouse effect that will cause more CO2 to go into
the Mars atmosphere. It might be considerably fewer. It also does
not account for CO2 and water vapor produced by cometary impact.

You know that H2O is a potent greenhouse gas? That would create one
hell of a steamy Mars...


Well if I combine all this info together:

"Observations of atmospheric leakage into space by NASA satellites,
such as DE2 in the mid 1980's and POLAR, have led to the conclusion
that the rate of leakage is more than is predicted by considerations
of the ability of particles to attain escape velocity.

One theory is that cosmic rays charged particles from space ionize the
molecules in the upper atmosphere, breaking them apart into ions and
electrons. At a height of about 120 km, a fair fraction of the
atmosphere is ionized. Because the electrons have such a small mass,
they are quickly accelerated through collisions and escape the
atmosphere. Such a process is sometimes referred to as "evaporation."

The loss of electrons to space leaves a balance of positive net charge
in the atmosphere, creating an electric field that can help pull ions
into space. Such charged particle outflows are known as "polar winds."
These charged molecules tend to follow magnetic field lines.

Ultraviolet light may play a part in the heating of these ions, giving
them enough energy to escape. Or cosmic rays can deposit their energy
in the atmosphere without ionizing any molecules. Effects of "charge
exchange " may also occur.

Luckily, there are also processes that replenish our atmosphere. For
instance, hydrogen is produced in the atmosphere through the
disassociation of hydrogen- containing molecules, such as water. Also,
some researchers estimate that most of the ions eventually fall back
to Earth along magnetic field lines. Although O+ is lost to space, it
is also replenished from the Earth. Similarly, H+ is lost, but it can
be replenished by the solar wind.

The ultimate fate of our atmosphere is a balance of many competing
processes and depends on many factors, only a few of which are
mentioned here. But perhaps the most important factor is mankind's
ability to alter the composition of the atmosphere through man-made
processes."

http://www.gi.alaska.edu/ScienceForum/ASF6/661.html

http://www.physics.uc.edu/~hanson/AS...c13/Page2.html

Evolution of Mars' Atmosphere
Early on, the terrestrial planets lost their hydrogen gas (H2) in
their atmosphere. Mars is massive enough to keep its water, N2 and
carbon dioxide. However, UV light from the Sun broke up the water
molecules, releasing the light hydrogen atoms to space (this happened
on Venus, too). The oxygen left over stuck around and reacted with the
rock, rusting the Martian surface, giving it its distinctive orange
color. Because of the large fraction of heavy elements still captured
by Mars (Argon, etc), it is believed Mars once had a more dense
atmosphere.

The Effect of the Solar Wind
Particles (mostly protons and electrons) come streaming from the Sun
all the time. They do not penetrate Earth's atmosphere because we have
a magnetic field, which acts like a shield to charged particles (they
can not cross the field lines easily!). When a large Solar storm
releases a large burst of particles, it's seen as an Aurora Borealis
on Earth, such as seen early this week, as the charged particles
spiral down on the Earth's magnetic pole. On Mars, however, there is
no magnetic field! Charged particles come streaming through at
enormous velocity and help to strip away molecules in Mars'
atmosphere.

---------------

Well, it all makes me wonder if warming Mars would just not lead to
the effect of putting gas into the atmosphere of Mars which would lead
to it being removed as fast as you warmed it! You superheated it with
comets - who knows?