Phobos Impacting Mars

[robtclements]

Exactly. In fact, since we're always tracking asteroids that will make close flybys (checking for ones that could potentially hit us), those would be far better candidates for grabbing and doing mining operations on. Heading all the way out to fucking Mars to hijack one of its moons and then bring it back to Earth is just a solution in search of a problem.

Basically correct, but the details are wrong. The potential impactors tend to have high delta-v requirements which make them a challenge but there are a whole class in near-Earth orbit (including quasi-moons like Cruithne) which could be moved with sails fairly easily. If Earth has any Trojan asteroids (still tbc) these could be moved more easily still

Value of this activity is dodgy but it can be done (& has been seriously investigated, at least for really small - ie ~10m class - objects)

With regards

 

[Jax]

Phobos is nearing Mars at a rate of 1.8 m every hundred years; at that rate, it will either crash into Mars in 50 million years or break up into a ring.

50 million years, god why can't we be alive for any of the cool stuff at least give me the supernova the galaxy is overdue for that is supposed to light up the sky for several weeks when it reaches us

 

[Christopher]

What's the likelihood of using a nuclear detonation to knock Phobos out of Mars orbit? At some point during Phobos' orbit around Mars and Mars' orbit around the Sun Phobos is heading towards the direction of Earth, at that moment a nuclear detonation of maybe several could give the Asteroid added thrust which would have it continue on it's journey towards Earth.

Wouldn't work that way. A single moment of thrust would just make its orbit slightly more elliptical. You need continuous thrust to accelerate an object out of orbit.

Besides, we've already established that it would be a ludicrous, pointless waste of energy to move Phobos from Mars to Earth and back again when there are plenty of Near-Earth asteroids that are much easier to get into Earth orbit, and when there are much simpler ways to get to Mars than using an asteroid at all.

Look, just read Kim Stanley Robinson's Mars trilogy. That'll tell you everything you could possibly want to know about the science and logistics of colonizing Mars.

 

[Chaos Descending]

...You need continuous thrust to accelerate an object out of orbit...

Not true. A single moment of impulse of great enough magnitude would do the trick just fine.

 

[Ronald Held]

In that span of time, the moon could be repositioned or used up for it's resources.

 

[Trekker4747]

What are the possibilities of knocking Phobos out of Mars orbit and placing it in Earth orbit?

My thinking would be to move it into Earth Orbit and then begin hollowing it out. The tunnels and rooms within the Asteroid would be reinforced and stocked up with supplies and resources for a Martian colony.

After years of supplying the Asteroid in Earth orbit it would be knocked out of Earth orbit and moved back to Mars where it would be made to impact Mars as slowly as possible.

The slow impact would be done by having the Asteroid enter Mars' solar orbital path in front of Mars travelling at just under 11000 mph, as Mars approaches the Asteroid and begins to overtake it it would enter Mars atmosphere. If you catch my drift.

 

[sojourner]

Phobos is nearing Mars at a rate of 1.8 m every hundred years; at that rate, it will either crash into Mars in 50 million years or break up into a ring.

50 million years, god why can't we be alive for any of the cool stuff at least give me the supernova the galaxy is overdue for that is supposed to light up the sky for several weeks when it reaches us

No thanks, any supernova that close has a good chance of frying all life on the planet.

 

[robtclements]

Not true. A single moment of impulse of great enough magnitude would do the trick just fine.

In what direction? I thought the theory was that you were sending Phobos into Earth orbit. This would be a solution to the problem: how do we launch Phobos in the general direction of Wolf 359? Assuming that the impulse drive didn't rip the moon to shreds in the process

 

[Christopher]

^Uhh, "impulse" doesn't specifically mean "that sublight engine they use in Star Trek." It refers to push or thrust in general; the word literally means "pushing against." The term "impulse engines" was intended as just a fancy term for rocket engines.

And it's just plain ridiculous to propose using an explosion to accelerate a moon out of orbit. You don't use TNT to get your car out of the garage. You just apply impulse by pressing down on the gas pedal. You want to change an orbiting body's trajectory, the sane thing to do is to apply continuous thrust. The idea of using a bomb to do the job of a thruster is just foolhardy, unless you're talking about something like the hypothetical Orion pulse drive using a succession of nuclear detonations to drive a ship. But that, too, employs a series of bombs imparting steady acceleration, not a single blast.

 

[ALF]

We've got to save it!
How much $$$ do we have leftover from those Important Wars?

 

[Gil T.Azell]

I highly doubt man kind will be around when it happens or we may have evolved into 'Q's' and will prevent it

Future destruction
Because Phobos's orbital period is shorter than a Martian day, tidal deceleration is decreasing its orbital radius at the rate of about 20 metres (66 ft) per century. In an estimated 11 million years it will either impact the surface of Mars or, more probably, break up into a planetary ring. Given Phobos' irregular shape and assuming that it is a pile of rubble (specifically a Mohr-Coulomb body), it has been calculated that Phobos is currently stable with respect to tidal forces. But it is estimated that Phobos will pass the Roche Limit for a rubble pile when its orbital radius drops by a little over 2,000 kilometers (1,200 mi) to about 7,100 kilometers (4,400 mi). Newer calculations suggests this will happen in just 7.6 million years from now. At this distance, Phobos will probably begin to break up and form a ring system which will continue to spiral slowly into Mars

 

[Silvercrest]

^Uhh, "impulse" doesn't specifically mean "that sublight engine they use in Star Trek." It refers to push or thrust in general; the word literally means "pushing against." The term "impulse engines" was intended as just a fancy term for rocket engines.

And it's just plain ridiculous to propose using an explosion to accelerate a moon out of orbit. You don't use TNT to get your car out of the garage. You just apply impulse by pressing down on the gas pedal. You want to change an orbiting body's trajectory, the sane thing to do is to apply continuous thrust. The idea of using a bomb to do the job of a thruster is just foolhardy, unless you're talking about something like the hypothetical Orion pulse drive using a succession of nuclear detonations to drive a ship. But that, too, employs a series of bombs imparting steady acceleration, not a single blast.

Don't worry, I'm sure a single humongous explosion will do the trick. But the OP may need to specify how many pieces he wants the moon to arrive in.

 

[robtclements]

You don't use TNT to get your car out of the garage.

To be careful in covering all the bases, you CAN use one-off explosions to move certain kinds of asteroids. A large bang just offset from a body rich in volatiles will vaporise the surface & can cause a secondary acceleration in the general direction of away. I don't believe that this would work to any significant effect with Phobos; but it could be used with a more cometary body

Approach is the current default position for any confirmed Earth-impacting rocks

It worries me that i still know this

 

[Christopher]

^Yeah, but that's just making a slight alteration in its orbit of the Sun, enough to get it to miss Earth. I acknowledge that setting off a nuke at Phobos would alter its orbit -- but as I said, it would still be in orbit, just with a different eccentricity or inclination. To get something out of orbit completely, you have to accelerate it to escape velocity, and if you want the object to survive the acceleration, you do it gradually.

 

[All Seeing Eye]

The idea of using a bomb to do the job of a thruster is just foolhardy, unless you're talking about something like the hypothetical Orion pulse drive using a succession of nuclear detonations to drive a ship.

Well if you go read my post again I DID say:

at that moment a nuclear detonation or maybe several could give the Asteroid added thrust which would have it continue on it's journey towards Earth.

 

[Christopher]

It's still not a good idea. There are plenty of simpler, safer ways to impart thrust to Phobos. A simple mass driver could do it, and I think that's how it was done in Robinson's trilogy. Heck, if you had enough patience, you could do it with solar sails.

 

[All Seeing Eye]

Heck, if you had enough patience, you could do it with solar sails.

Yes I know that too, that's why in a previous post I said:

If time is not a problem then the Asteroid could be moved with little fuel and not "shittons" of it.

 

[Ronald Held]

Since people are worried, is that rate a current estimate or good for a miilion years? i have not seen that simulation.

 

[Trekker4747]

Since people are worried, is that rate a current estimate or good for a miilion years? i have not seen that simulation.

No one is worried.

Well, one person is worried but...

Well, we'll just leave it as no one is worried. I mean, Luna is widening its orbit from Earth and no one is proposing any drastic plans to prevent that from happening (as it'd have disastrous effects on Earth's with messing up the tides and all) because it's not going to happen for a very long time. Such a long time we're better off worrying about the whole "Red Giant" thing first.

 

[Jetfire]

Scientists say that a star's lifetime is around 10 billion years old, and right now the Sun is about 5 billion years old, so it should be (you can do the statistical math). When the Sun goes supernova, be ready to say bye bye to mommy.
After 10 billion years is up the Sun will start to expand and swell up like a fat man at an all you can eat bar. As it increases in size, it will devour Mercury, Venus and com a little too close to home. As the temperature increases we will be toasted beings, actually dead ones. The crust of the sun would remain rather cool than normal, only about 3,000 kelvin. Its normal temperature is about 6,000 kelvin. Within a quick time the star's core collapses and then explodes, leaving a black hole, matter and some heat from the sun being blown out into space. The explosion can be seen from many galaxies away due to the bright light it emits. Strong gravitational pulling occurs as the black hole sucks everything into oblivion. Now on your merry little journey to oblivion, planets, comets and mass objects may collide creating catastrophes within a catastrophe.

http://library.thinkquest.org/C001245/SunSn.html

Where will be a "comfort zone" when the sun swells? Jupiter? Saturn? Neptune?