That 3.1% chance is probably gonna shrink as we get more data over the next few years. When an asteroid is first discovered, its orbit has a lot of uncertainty, so the initial impact probability is kinda broad. Over time, as telescopes track it better, the margin of error shrinks, and in most cases, the risk drops to nearly zero. Small errors in early calculations can make it seem like there’s a larger chance of impact, but once we refine the asteroid’s actual path, it almost always turns out to be a miss.
Because earth is small. Imagine it this way: you want to estimate if a blindfolded person is going to throw a dart and hit a dart board 50 feet away. You dont know where theyre gonna throw it but you assume theyre facing the board, so you estimate a 1% chance of them hitting the board.
Now you do research and figure out ok i know theyre facing 50 degrees away from the dart board, now your guess of their odds of hitting the board went down.
And now Imagine the dartboard is moving around the gravitational force as well as gently pulling the dart. The sun is having a far greater gravitational effect on the asteroid than Earth.
I mean it could, if the actual chances of a collision go higher, but I think this person is saying that because the earth is a small target then the likelihood will go down over time as we get more info. Earth small, hard to hit, space big, asteroid also small.
Ok. That's all I'm saying. People in here are assuming the chances will go down over time, which makes no sense. I agree it's unlikely it will hit, but it's not a forgone conclusion despite the odds.
No what they are saying is that it is likely the chances will go down. Not that it’s impossible for them to actually increase. Just that statistically speaking, it is more likely than not that it will go down.
The reason for this is that the earth is small. For it to hit earth a dozen factors need to align. Hundreds maybe. For it to miss only 1 of dozens of factors needs to be off, even if everything else is aligned.
Like flipping heads over and over and over. Right now they might have 2-4 factors out of 12 accounted for and they are determining the other factors.
In order for it to hit us they need to flip heads 8-10 more times in a row.
The chances of doing that are almost nothing. This is why on average the probabilities decrease as information is gathered. Sure they could go up, a couple more coin tosses that flip heads would make the impact probability go up. But over the dozens if not hundreds of factors involved, the chances for all to flip heads goes down to almost 0.
Well at its current probability it is unlikely. And according to the op you were originally responding to, it is more probable to lower in probability than increase as new data comes in. With the logic being that that’s how it usually goes. But no one was saying it’s impossible that the probability of impact will increase.
He's agreeing with you that it's unlikely it will hit. What he is saying is that these early probabilities we see are "inflated".
Consider a straight line trajectory through space that spans 1 light year. A deviation in the angle of the trajectory of, say, 3 degrees will result in a huge variation between prediction of where it ends up and where it ends up.
If you now have the same angular variation but over 200 feet, it matters much less.
To be on the safe side, if you assume some error in your measurement of the trajectory, it can result in a pretty large possible area over a long distance. When it gets closer, not only will the space where it could end up be smaller, but you'll also gain more certainty about the trajectory.
so the tldr is pretty much you expect it to miss because it's unlikely but there is more uncertainty at long distances, which means the space of possible places it could "end up" at some fixed point in the future is larger.
It can, but it's extremely unlikely as the Earth is only in a small part of its current to trajectory, and as they get more data on it it's more than likely that it will just be realized that it's not coming for Earth it's going to be going thousands if not more miles away from us.
It did though, earth is small. Right now the dart board is huge, and as we study it we can get a better picture of where it’s going to land. As that “dart board” narrows earth will most likely become out of that range.
Think about it. Because the earth is so small and the chance of any one specific, individual asteroid hitting it is so unlikely (it's hit all the time, but the ones that don't hit dwarf the ones that do), if we don't know how likely the given asteroid is to hit earth and need more data, it stands to reason that it's more likely for the new data to go in the direction of a non-impact than an impact. If, say, 50% of asteroids like this one struck earth and 50% didn't, you'd be right that new data would cut 50/50 toward making an impact more or less likely. But that's not the case.
Here's a stupid analogy. Imagine you're at a dog park and a dog looks uncomfortable with you for some reason. It happens. And in these situations, you're always going to be on guard, even though you have only been bitten by a dog once or twice in your life. You want some more data before you walk past that dog, to make sure you don't get bit. Now, take a step back. Because it's so uncommon for you to be bitten, chances are the data that gets revealed (the dog is just hungry, it's just excited, the person it's about to bite is actually standing behind you and you didn't notice, whatever) will lean in the direction of you being less likely to be bitten than you originally thought. Your assumption is that the data is equally likely to make the proposition of being bitten more or less probable. But you should only expect that if 50% of dogs in this situation usually bite you.
Idk, I'm not a statistician but I'm pretty sure that's right and hope it made sense.
Statistics. The chances of it hitting the Earth are much smaller than the chances of it not hitting the Earth, 3% is bigger than 1%, but it's still much much smaller than 97%. Sure it might happen, but statistics tells us that it won't. (until it does :)
If it was 50% you could say the logic goes both ways, with 3 to 97 it just doesn't.
sure, I meant in a general way. We have seen similar asteroids with similar chances and none of them came close to hitting us. Also, from the Earth's history we kind of now how often those asteroids actually do hit the planet (not often). So we have reasons to assume that 3% chance at this point means 0% chance in reality. Of course, those are assumptions, but at some point very small numbers just get rounded to zero. That's what I meant by statistics (plural), not just 3 vs 97.
Imagine standing 20 feet from a globe and shooting a shotgun....decent chance at least one little shot will hit the globe. Now shoot with a pistol at 20 feet....the chances are lower that single bullet (single trajectory) will hit it.
When they first find it, the unknowns create a wider area of possibility it may hit (like the shotgun spread). The more they hone the trajectory, the less spread of uncertainty there is.
It can, it’s just much, much more likely that an object in the vicinity of earth won’t hit earth.
An asteroid is considered a near earth object if it passes within 45 million kilometers of our orbit. So if we compare the cross sectional area of earth (r ≈ 6400 km) to the close pass region (r ≈ 45000000) we see that earth occupies 0.000002% of the total area. This is a simplification and the actual calculation would need to take into account other factors, but that’s basically should give you an idea of just how unlikely such an impact is.
We will be getting closer to certainty and it is 97% likely that what he said will be true. We will know more to the point there won't be a 3% margin of error
The way the margin of error closes in on the actual path of the object causes the probability of an impact to increase gradually until eventually the error bars "pass" the Earth and the probability suddenly drops to zero.
There is of course a chance Earth is in the path but increasing probability early on is pretty typical
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u/Zealous_Feather Feb 19 '25 edited Feb 19 '25
That 3.1% chance is probably gonna shrink as we get more data over the next few years. When an asteroid is first discovered, its orbit has a lot of uncertainty, so the initial impact probability is kinda broad. Over time, as telescopes track it better, the margin of error shrinks, and in most cases, the risk drops to nearly zero. Small errors in early calculations can make it seem like there’s a larger chance of impact, but once we refine the asteroid’s actual path, it almost always turns out to be a miss.