REal probability question

Suppose you accelerate a probe to 1/10 the speed of light in a random direction away from the Sun. What are the odds it will crash into a planet or a star within the lifetime of the Universe?

The chances that it will crash with something is, of course, 100%.

I'm going to go with essentially 0. This is based on 2 things: first, if it does crash into something it's probably going to crash into something else first, like an asteroid, or something nebulous that makes it fizzle and die.

Discounting or ignoring this possibility, the sheer distance that most stars & planets are from our sun means the likelihood of choosing the exact coordinates to hit one is infinitesimally small. Even though there are millions/billions of targets, a very tiny # times billions is still very tiny.

I am not an astronomer.

As a random addition to this thought, I estimate the probability of hitting Jupiter, probably the most likely target in the universe, as 2.0 e-9, or 1 in 500 million.

There's a lower bound, but if you add up a bunch of numbers much smaller than that, you're not going to get a much bigger number.

Quote: dwheatley

As a random addition to this thought, I estimate the probability of hitting Jupiter, probably the most likely target in the universe, as 2.0 e-9, or 1 in 500 million.

Since the probe is moving away from the Sun, it would ahve to pretty much circumnavigate the Universe in order to hit Jupiter.

The thing is that stars and planets do collide on occasion. The latest theories say that a Mars-sized body hit the proto-Earth long ago, without quite enough force to shatter our world entirely. Likely the result was some added mass and the Moon.

Quote: Nareed

Since the probe is moving away from the Sun, it would ahve to pretty much circumnavigate the Universe in order to hit Jupiter.

I don't get it. If the probe was moving away from the sun in the direction of Jupiter, why couldn't it hit on the first try?

How much effect is gravity allowed to have on our question?

Quote: dwheatley

How much effect is gravity allowed to have on our question?

Extremely little.
When consider its effect, it makes each object in the univsere only a tiny bit larger.

Quote: dwheatley

I don't get it. If the probe was moving away from the sun in the direction of Jupiter, why couldn't it hit on the first try?

It could. But I dind't say where the probe is launched from. Assuming the objective is to wait and see when it hits something, you'd launch it from the Kuiper belt.

Quote:

How much effect is gravity allowed to have on our question?

As much effect as gravity has in the every day affairs of the Universe. Ditto for "dark energy," light pressure, friction from assorted debris scattered all over the Universe, etc.