/sci/ - Science & Math

[Anonymous No.9572724]

>2060
>mars is colonized
>lots of commercial space travel between mars and earth
>spaceships use hydrogen/oxygen mixture as fuel
>massive amounts of water being turned in to rocket fuel on earth and mars
>spaceships do transfer burns in space
>water exhaust is now permanently and irrecoverably lost in earth/mars/solar orbit in form of steam
>eventually, both earth and mars have no water left

Why even bother trying.

[Anonymous No.9573022]

You ever read Asimov's "The Martian Way"?
Spaceships have a cheap energy source, the proton micropile (which I imagine is fusion), but it superheats water into steam for thrust.
A politician determined to starve the colonies rants about the loss of Earth's water. He makes an emotional issue out of it, though the numbers don't support him.

"Seems that Earth has four
hundred million cubic miles of
water in its oceans and each cubic
mile weighs four and a half bil-
lion tons. That's a lot of water.
Now we use some of that heap in
space flight. Most of the thrust
is inside Earth's gravitational
field, and that means the water
thrown out finds its way back to
the oceans. Hilder doesn't figure
that in. When he says a million
tons of water is used up per flight,
he's a liar. It's less than a hun-
dred thousand tons.

"Suppose, now, we have fifty
thousand flights a year. We don't,
of course; not even fifteen hun-
dred. But let's say there are
fifty thousand. I figure there's go-
ing to be considerable expansion
as time goes on. With fifty thou-
sand flights, one cubic mile of
water would be lost to space each
year. That means that in a mil-
lion years Earth would lose one-
quarter of one per cent of its total
water supply!"

[Anonymous No.9573865]

>>9572724
Asteroids, comets, moons are abundant of water.

[Anonymous No.9574171]

>>9572724
Do you know there are comets with more water than Earth, Moon and Mars together right?

[Anonymous No.9574446]

The problem with Mars is that the core is no longer molten, thus weak magnetics and no atmosphere.

[Anonymous No.9574449]

>>9574446
Wrong, there was molten lava 2000 years ago.

[Anonymous No.9574464]

>>9574449
Then why is the atmosphere so thin? Why is the gravity weaker? Why no magnetic poles? Cuz Mars died, fag.

[Anonymous No.9574469]

>>9574464
>Why is the gravity weaker?
Are you serious?

[Anonymous No.9574474]

>>9574464
Wait for Insight lander to determine internal geology.

[Anonymous No.9574478]

>>9574469
The gravity on Mars is weaker than Earths gravity. That is a fact.

[Anonymous No.9574633]

>>9574449
>magma comes from the molten core

[Anonymous No.9574840]

>>9574171
Let's check the numbers:
That big blue sphere is the total water of earth, it's 1200 km in diameter.
At best a comet is 80% water so you need a comet of 1500 km in diameter to match that.
The biggest known comets are 200-300 km, and even a big comet like Hale-bopp is only 60km, while the most common are just a few km.
I'll leave the math to you.

[Anonymous No.9575125]

>>9574478
Because it's a smaller planet, it doesn't matter if it had a earth like environment with breathable air and a nice temperature, it'll still have the same gravity it has now.

[Anonymous No.9575164]

>>9574840
we know only about surface water the ocean,rivers glaciers etc their are large reservoirs inside the earth

[Anonymous No.9575309]

>>9575125
WRONG. The atmosphere of a planet is maintained by GRAVITY. No gravity and the solar winds blow your atmosphere away. No molten core, no N/S poles, and thus LIMITED OR ZERO gravity.

[Anonymous No.9575462]

>>9575309
Let me put it simply

If we had the capability of increasing Mars' mass to have Earth Gravity we may as well build a fucking planet from scratch or terraform Venus as it's size and gravity is only a fraction less than Earth.

[Anonymous No.9575467]

Water is fucking everywhere, we're not going to run out of it.