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62 votes

Could an astronaut in a near-future space ship survive transit through our asteroid belt?

Yes they could. Very Easily. Contrary to myth, the asteroid belt is very nearly empty. (See https://physics.stackexchange.com/questions/26712/what-is-the-average-distance-between-objects-in-our-...
Mark Olson's user avatar
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54 votes

5km artificial planet, with same gravity as on Earth

Sorry in advance. You won't like this answer. The "stuff" in white dwarf matter is more specifically known as degenerate matter. Basically, the more tightly you crush this matter, the more the ...
Cort Ammon's user avatar
  • 132k
52 votes

What would be the effect(s) of this asteroid?

Everything Dies The combination of mass and velocity is inescapable. The follow-on asteroids don't matter. The initial impact will do the trick. Half the mass of the moon is approximately 36 ...
jdunlop's user avatar
  • 32.1k
51 votes

Could an object from space crash into Earth and set off a majority of the nuclear bombs created?

The meteorite started the war. The country hit by the meteorite considered the impact an indirect attack by the nations that did not warn them. For example; foreign space agencies collectively ...
PStag's user avatar
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48 votes

Would it be possible for hunter gatherers to accidentally colonize an exoplanet, from an asteroid knocking a rock containing a cave into space?

The rocks that ceiled the hunter gathers in the cave for many generations are ejected from the entrance to the cave when the rock crashes into the planet, allowing the hunter gatherers to leave the ...
L.Dutch's user avatar
  • 291k
43 votes

Can an asteroid go through the sun?

No. I'm not knowledgeable enough to derive what would happen in this scenario, but I bet you Randall Munroe is. More specifically, he knows what happens to a baseball that travels at .9 c from the ...
Qami's user avatar
  • 6,991
38 votes

Would it be possible for hunter gatherers to accidentally colonize an exoplanet, from an asteroid knocking a rock containing a cave into space?

Unfortunately, such a plan would be doomed from the start. It's not enough to simply reach escape velocity while on Earth's surface, because Earth has an atmosphere that will quickly slow you back ...
Cadence's user avatar
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34 votes
Accepted

Extremely small planet to live on

Our known quantities are: Radius of the body: 50 metres Density of the body: same as Earth's, 5515 kilograms per cubic metre This is enough to calculate the acceleration due to gravity on the ...
Gallifreyan's user avatar
34 votes

What would be used for "coordinates" on a large asteroid?

My suggestion would be that you select a point on the asteroid to act as a pole. Perhaps the point of first landing? Then, using that point and asteroid's centre of gravity as references, you can map ...
Arkenstein XII's user avatar
32 votes

5km artificial planet, with same gravity as on Earth

A first approximation Let's calculate surface gravity. Assuming an object of density $\rho$ and radius $R$, the surface gravity is $$g=\frac{4\pi}{3}G\rho R\tag{1}$$ For a white dwarf, $\rho\sim10^9$ ...
HDE 226868's user avatar
  • 101k
32 votes

Can an asteroid go through the sun?

For certain values of "through" I'll give a definite yes. To be clear, the Sun is much too dense to permit a near-central passage of anything less dense than white dwarf matter at merely ...
Zeiss Ikon's user avatar
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32 votes

What are the repercussions of two asteroids in the asteroid belt colliding?

Probably nothing Robert Rapplean's answer is correct (upvoted) that without further information it is not possible to guess at an answer without more information, but there are some additional factors ...
KerrAvon2055's user avatar
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31 votes

Would it be possible for hunter gatherers to accidentally colonize an exoplanet, from an asteroid knocking a rock containing a cave into space?

ALIEN ABDUCTION (circa 20,000 BCE): The only way this scenario works that I can see is if there is an intervening intelligently designed space traveller involved transporting the people. It could ...
DWKraus's user avatar
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30 votes

Could an object from space crash into Earth and set off a majority of the nuclear bombs created?

Yes and no. An asteroid, or any impact really, cannot set off thermonuclear warheads, in the sense of causing a nuclear blast. These warheads are composed of disks of conventional explosives that ...
Cadence's user avatar
  • 38.5k
30 votes
Accepted

What would be the effect(s) of this asteroid?

Earth is gone. The Moon is gone. Mars gets nuked. The entire Solar System becomes hotter than Mercury for a couple days. The Sun will appear to glow up to 12,000 times brighter. The Solar System will ...
BBeast's user avatar
  • 2,161
30 votes

Delivery of minerals to Earth from the asteroids by artificial meteorite or solid metal glider

Refine as much as possible on the asteriod. Keep your as much of your refinering chain as close as possible to your mining operation, moving 1kg of high grade ore vs 1kg of low grade ore requires the ...
Ash's user avatar
  • 44.2k
29 votes
Accepted

Why wouldn't the world have advanced warning of a significant asteroid/comet strike?

The near-Earth objects we look for are mostly in the plane of the ecliptic, because that is where the vast majority of solar system material not in the Sun is to be found. The object that is about to ...
SoronelHaetir's user avatar
28 votes

How difficult would it be to turn the Asteroid Belt into a single body? What's the best method?

How difficult would it be? Unfortunately, your timeline is too tight for any of the easy options to work. The mass in the asteroid belt is highly concentrated. Between them, Ceres (~30%), Vesta (~...
Mark's user avatar
  • 17.9k
25 votes

Is it easier to mine asteroids than planets if teleportation technology exists?

One thing to consider is the difficulty of retooling. This is, oddly, a point in the favour of asteroids. Simply put: when moving your operations from one planet to another you have to consider ...
Joe Bloggs's user avatar
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24 votes

What would be used for "coordinates" on a large asteroid?

Whoever is going to be on that asteroid will necessarily used radio communication to keep in contact with the rest of the crew. To ensure communication a network of antennas has to be established, ...
L.Dutch's user avatar
  • 291k
22 votes

What would happen if a little less than half of the moon crashed into the Atlantic ocean?

The mass of the Moon is $7.3 \times 10^{22}$ kg. Half of it would be then $3.6 \times 10^{22}$ kg. That mass would impact Earth at about 11 km/s, releasing an energy of about $217 \times 10^{28}$ J, ...
L.Dutch's user avatar
  • 291k
22 votes

Why put a big rock into orbit around Ceres?

You don't need to find a way to tow it there. (It was possibly made to generate power, see the end of my answer.) It's a slag heap! You have already determined mining on Ceres is a booming, and mining ...
EdvinW's user avatar
  • 3,130
21 votes

What would be used for "coordinates" on a large asteroid?

I'd maybe consider using the axis of rotation - it would be a very rare asteroid that isn't rotating somehow. Imagine sticking a skewer through the asteroid along the axis. That would give you a top ...
PainlessDocJ's user avatar
21 votes

What would be used for "coordinates" on a large asteroid?

I would suggest that they use a GeoHash which subdivides the asteroid into a hierarchical grid that can be navigated based on any desired granularity https://en.wikipedia.org/wiki/Geohash The origin ...
bicarbon8's user avatar
  • 339
21 votes

Why wouldn't the world have advanced warning of a significant asteroid/comet strike?

So a counterpoint to your view. The world thinks there is no warning system, not because it doesn't exist, but because the world has no way to respond to this information. A world ending meteorite ...
Flotolk's user avatar
  • 520
20 votes
Accepted

What is our planetary defense capability against an Earth life destroying object?

First, a little digression on comets: the coma or "hair" (that's the literal Classical Greek translation) of the comet is indeed very, very long, but it's also incredibly rarified (not dense). More ...
Cadence's user avatar
  • 38.5k
19 votes

What would be the effect(s) of this asteroid?

5% of lightspeed is insanely fast for an asteroid. Earth is gone. It doesn't matter where that giant asteroid hits. Luna is gone. Some of the combined mass might form a new belt, but much will be &...
o.m.'s user avatar
  • 117k
19 votes
Accepted

Could a planet's tidal forces break an asteroid passing very close to it?

Yes, what you are asking is exactly the definition of the Roche limit In celestial mechanics, the Roche limit, also called Roche radius, is the distance from a celestial body within which a second ...
L.Dutch's user avatar
  • 291k
19 votes

What are the repercussions of two asteroids in the asteroid belt colliding?

There is no way to even start answering this unless you know the relative speed and direction of the two asteroids. On the low end, they would gently merge into a single larger asteroid, with some ...
Robert Rapplean's user avatar
18 votes

Plausible Reason for Asteroids Being Close Together

We need look no further than Saturn's rings. Saturn's rings are made up of billions of particles ranging from grains of sand to mountain-size chunks. Pioneer 11 passed through the outer rings and ...
JBH's user avatar
  • 125k

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