1-in-3,200 chance* that a fiery satellite chunk will hit someone on Friday Small fiery pieces of what was once a climate-monitoring satellite will hurtle towards the Earth's surface this Friday. Unless you live in Greenland, Siberia or Antarctica, watch out for dazzling lights in the sky as red-hot lumps of NASA-grade aluminium descend upon our planet. The space agency predicts that the debris from …
This is all an abuse of statistics.
Now, I'm no maths genius, so please correct the glaring ommisions here.
As pointed out above, the 1 in XX chance of hitting someone means that the essential algorithm is reversed.
ie, if you were to transpose yourself from the lottery example into the satellite example, you would not be a person on the earth, you would be the satellite.
Calculating how likely it is to hit me is beyond my number crunching skills (I'm more of a logic cruncher).
However to take the lottery as a comparison.
There is 1 draw per week, with very long odds. However, _millions_ of people enter, so there is regularly a winner. If millions of satellites were to enter the atmosphere every week, then in all likelihood, someone would be hit each week.
By the same reasoning, if only a single person (and no one else) were to buy a ticket this week, then they would be less likely to win the lottery than be hit by this satellite (according to the above numbers that I can't confirm)
This is how you'd make the two equivalent. Essentially, a single, given lottery ticket winning is the valid thing to compare to a single satellite, not the entire lottery.
You see the results of this in the satellite odds themselves. The 1 in 3200 is the total system involved. The odds to hit someone, anyone. If you were to calculate what the odds were for someone, anyone, to win the lottery. I'd fully expect that they'd be in the same order as these. Maybe a bit lower, given that there is generally a winner each week or two.
Here ends the lesson, corrections sent to my good friend, Mr Don Kiddick or his special friend, Ben Dover.
@Josco - I believe there is a 1 in 54 chance that you will win something on the lottery if you enter a single line, but there is a 1 in 21 trillion chance that you will be hit by the satellite. While I accept that 1 in a million chances come up nine times out of ten I can't see that 1 in 21 trillion is more likely than 1 in 54. Maybe it's because your calculator won't go up to 21 trillion that you can't do a simple probability calculation like that.
No there isn't a 1 in 3,200 chance I'll be hit by fiery chunks of satellite, there's a 1 in 3,200 chance that some body on the planet will be hit by a piece of satellite which means the the chance of me being hit is 1 in 3,200 x the number of people on the planet, which is about 7 billion.
So I personally have a 1 in 22400 billion chance of being hit by a piece of satellite which is pretty slim....
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1-in-3,200 chance of hitting a person? Really.
Presumably that would mean, on average, the area of the Earth it could hit is 1/3200th covered in humans? I'm a bit sceptical of the maths on that one.
1-in-3,200 chance of hitting a human, or something-made-by humans (house, road etc.) sounds more reasonable perhaps.
You have to remember that Americans are mostly obese and therefore cover a much greater proportion of the ground than other people, thus making it much harder for the flaming lumps of satellite to sneak between the bellies and bingo wings to actually hit the ground...
"The smouldering lump will remain the property of the United States and must be turned over to local police." - So I guess they will also have to admit liability for any damage/injury sustained. I hope it hits my car. I've always wanted a Lamborghini.
Funny that, they confiscate my bottle of water and razor blades on planes, on much much smaller odds!
Also, "remain the property of the United States" hey good luck with that if it lands on _my_ lawn. I wonder if they make Afghan civilians bring the bullets back to the local police. Surely they remain the property of the USA, too? An interesting question springs to mind: if the debris remain the property of the USA, do they accept full criminal liability for the damage (and/or casualties)?
and to back up the claim to keep possession of said lump of ex-satellite.....
surely the plan to burn it up in the atmosphere to dispose of it is like throwing something in the bin because you have no use for it and dont want it.., but wanting it back because somebody else does?
windows user icon because it looks like Albert Steptoe
The exact time the satellite begins its reentry depends on many factors, but mostly the density of the atmosphere where it is orbiting. Because of heating from solar radiation the atmosphere's density changes over periods of hours and days which can dramatically change the amount of drag being experienced by the satellite.
Added to which this satellite has probably lost all attitude control so it will be tumbling and experiencing variable amounts of drag, all of which make predictions a bit less - well - predictable.
An asteroid on the other hand approaches the Earth through a vacuum at a relative speed of several to tens of kilometres per second following the laws of Mr. Newton. The atmosphere only has any effect on it during the last few seconds before it carves out a dent on the surface.
... and if you want to track it, heavens-above.com have a nice, real-time view of who's under the flight path.
The irony is that if it does actually come down on top of some unfortunate person, they will be one of the few, verifiable, casualties of climate change. Though not from its earthly effects, but our efforts to do something about it.
I can just see that at my local cop-shop:
"'Allo, 'allo. What's this, then?"
"It's a small piece of downed satellite."
"Look, I'm busy drinking tea and doing the Sun crossword. Do you know the penalty for wasting Police time?"
"But, sir. We're supposed to hand these bits in for you."
"Really? Who told you that, then?"
"NASA."
"Oh yeah? And I'm bleedin' Sherlock 'Olmes! Go on, get out you bleedin' idiot!"
At which point NASA send round the big, black limos to 'take care of you' for not returning their smouldering lumps of space crap.
Still, the light show should be good.......
...that cooked on plasma as if fell may have become radioactive while flying outside earth atmosphere, or contaminated with radioactive dust by any means. I wouldn't touch it, and possibly cover it with a lead box, until the MIB pick it up. Only a geiger counter in hand would ensure it is even safe to get near it.
would disagree with the property claim by NASA, backed up by the gov of the US of A. But then, again... Iranian ebay perhaps?
And the North Koreans wouldn't mind wagging the dog, I'm sure. And then think of the Russians, the Chinese, they do sit on a bit of an estate and their asking price might not be worth making too much noise about NASA property claim...
If it landed on Dale farm in Basildon then I'm sure there would be alot of happy tax payers.
And before you complain it will be empty on friday and the whole cleanup would have to be born by NASA saving alot of money - that is the logic at work here, anything else is in your own evil minds :p.
"The smouldering lump will remain the property of the United States and must be turned over to local police."
Oh yeah? I know the US government seem to think their law applies around the whole planet, but it doesn't. I'd like to see them make that stick some countries. Personally I hope it lands (without harn to any life) in a country unfriendly to the US and that the people that find the bits make a fortune out of it.
I just love the fact that NASA think it's a big problem that one of their satellites may be damaged by space debris, but don't seem to think it's nearly as big an issue that somebody or their property may be hit by NASA's own space debris. Irony? They've heard of it.
It would have had no where near enough fuel to do that. To escape our gravity pool it would probably have to increase its speed from about 8km/s to 11km/s. Don't forget, that kinetic energy is proportional to speed squared. It also had a lot of help to get to 8km/s, in the form of a much bigger launch rocket.
To make a significant change to an orbit you need quite a lot of delta-V
To escape, you've got to burn fuel to get all that delta-V.
However, to crash you only need to burn fuel enough to enter an aerobraking scenario, which gives you delta-V for free, and you get even more when you hit the ground.
Back from 1986 to 1991 I worked on the flight software for UARS. The onboard computer was a NASA Standard Spacecraft Computer-1 that I think was made by IBM. It used magnetic core memory, which was great because you could turn one side off for years and when you powered it back up, not a single bit was flipped. Memory words were 18 bits, so we did everything in Octal, not Hexadecimal (since 18 bits made 6 octal digits). The design language was FORTRAN 77. Once we got the FORTRAN running in simulation, we converted it to NSSC-1 assembly language manually (no compiler). Seems to me it ran about 150K instructions per second. UARS was a good satellite and worked for a long time.
if I am hit by a falling piece of debris on Friday, do I
i) tell NASA to *** off, this isn't your piece of debris it's just A piece of debris... no that isn't half your logo on the side
ii) claim $10M from NASA for injuries caused by a falling flower pot
iii) roll over and die
I suppose it depends on the radiation count and accuracy...
Yet on Friday night millions of people across Europe will be clutching tickets that have 1 in 116,531,800 chance of ruining their lives with a single cheque for far too much money.
Better get the tin hat out in case a chunk falls through the roof just as my numbers are drawn...
"Sadly, if you do manage to catch a chunk of satellite, the US government expressly forbids you from selling it on eBay. The smouldering lump will remain the property of the United States and must be turned over to local police".
So, if said smouldering lump kills you and/or your family, your heirs will be able to prosecute the US authorities for murder (or, at the very least, manslaughter).
No, you say? Why on earth not? Oh, I see... the US government is free to bombard any part of the planet with impunity, not caring whom it kills or renders homeless - but if anyone dares to claim ownership of the debris that killed their nearest and dearest or demolished their home, THAT would be a crime?
Divide that part of the world's surface, where the bits are likely to fall (that's most of it), into a grid and have a sweepstake or similar where you can predict a likely impact area. Score one point if it's in the sea or an unpopulated area, two points for a populated area and three for an impact on a human. Charge each entry a Pound, Dollar, Euro or whatever and share the total take amongst the winners, minus a small administrative charge of course. More fun than a lottery.
"As of 9:30 p.m. EDT Sept. 22, 2011, the orbit of UARS was 110 mi by 115 mi (175 km by 185 km). Re-entry is possible sometime during the afternoon or early evening of Sept. 23, Eastern Daylight Time. The satellite will not be passing over North America during that time period. It is still too early to predict the time and location of re-entry with any more certainty, but predictions will become more refined in the next 24 hours."
From:http://www.nasa.gov/mission_pages/uars/index.html
"The satellite will not be passing over North America during that time period."
That about says it all. As long as stuff won't be raining down on North America everything is fine then.
There is this report http://www.bbc.co.uk/news/magazine-15023115 on the BBC which includes the statement:
“The debris will include three batteries, four wheel rims and four fuel tanks, and their speed when they hit the ground or the ocean will vary.”
The batteries and fuel tanks are quite understandable but when read in conjunction with the rims, one has to ask “Who’s made off with the tyres?”
(There’s a sub-joke here where someone will say that he probably has but this is not the place to discuss the new Tardis design.)
...is made on the erroneous assumption that all 7 billion people on earth are outside, watching the downfall (pun!).
In fact chances are even much smaller, that any human being is hit. So all those with the tinfoil hat, swap it for a drink in your pub, somewhere inside, when the parts land.
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