Slashdot Mirror
NASA's Deep Impact
NivenMK1 writes "The Seattle Times has an interesting article on NASA's plan to nail the comet Tempel 1 with a chunk of copper the size of a bathtub on July 4 this year. This copper 'bullet' is intended to strike the comet at approximately 23,000 mph and hit with a force equivalent to 4.7 tons of TNT.
Scientists hope to discover what exactly the comet is made of and what changes have occurred to the outer layers with reference to the core."
You want to analyse the comet, which you can do by looking at the emission lines of the cloud forming after the impact, ect.
An explosive is normally composed of chemically very reactive components, that can react with each other and the material of the comet, making it very hard to discern what WAS there and what was created by the blast.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Explosive will heat up the comet, leave pollution, and make analysis of the dust very hard....
The article doesn't state if this velocity is relative to Cape Cod or relative to the comet. It makes a big difference.
Look at the numbers:
The impact power of the copper rod is 4+ tonnes of TNT. IF you wanted to double the blast, you would have to send more than 4 tonnes of explosives.
at 30km/s+, the kinetic energy of the material is bigger than the chemical energy of explosives.
The added energy just doesnt matter anymore because it would be difficult to time the blast, plus the softness of the explosives would reduce the impact penetration.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
Nasa is conducting the experiment precicely BECAUSE nobody know what will happen next. If we knew with certainty what was going to happen, THEN there wouldn't be a very good reason for carrying on with the experiment.
Last year they spent $200 billion blowing up comet Baghdad and we're all still waiting to see how that cliffhanger's going to end! This time it's cheaper and it doens't involve killing anybody.
Hitting comet vs. Missile defense:
1.Long time to learn precise trajectory of comet vs. few minutes with missile.
2.One comet (and big at that) vs. multiple warheads and fake warheads x10.
3.Comet is in a microgravity enviroment, bullet could stop and wait for comet vs. warheads - where can you "wait" for warhead? - you would need constant thrust to maintain position.
4.You miss the comet NASA looks bad for a few weeks. vs. you miss the missile - some city looks bad forever.
I've loved astronomy on a casual basis since childhood and I think it's important to mankind. I'm not one of those people who thinks we should abandon NASA spending because there are still underprivilidged marmasets living in a swamp somewhere or whatever.
But isn't this kind of, uh... wrong? Possibily destroying a comet? It seems so destructive to possibly break apart something that's been circling our sun for millions of years.
I understand that comets are more like "dirty snowballs" than things of infinite beauty, and I can definitely understand the scientific reasons for this mission because they're going to get all kinds of data that they couldn't get otherwise.
This seems kind of wrong to me, though.
OtakuBooty.com: Smart, funny, sexy nerds.
I don't think the emission lines would actually provide much of a problem, it would be pretty easy to filter out the gaseous emissions of the explosives... I think the greater problem would be the unpredictability of the momentum problem if you added a chemical explosion. With a solid projectile, you can expect to learn a lot about the comet simply by what happens to the path of the intercepting projectile- ie shooting the snowball example. But, if you shoot a snowball with an RPG, or an iceball with an RPG, it's a lot harder to look at the resulting dispersion and tell what the target was made of after the fact.
---
she won't let you fly, but she might let you sing
No, spending $311 million on a scientific experiment , when you already knew what would happen would be a waste.
It's not a majority of people.
2004 Election Results
When millions disappear from earth, it's not aliens, it's the rapture.
The other 5 tons of TNT of explosion comes from the kinetic energy.
Mod down posts with a "Free Mac Mini/iPod" sig, they're spam!
And I quote:
"If we knew what we were doing it wouldn't be research."
- Albert Einstein
I was just trying to show that it was not as rosy, as the parent post indicated.
I am from Northen Europe, and I just have to look out the window, to see a better place that America.
space should be like an international nature park. you dont go just randomly blowing things up willy nilly.
Spending 311 million dollars without knowing what happens next doesnt seem a very nice idea.
I am sure there is military research aspect in this project too. The ability to hit a comet with a bathtub-sized hunk of metal is probably good practice for hitting an adversary's satellite with a bar of soap-sized hunk of metal.
I highly doubt this is purely civilian science in action.
The only athletic sport I ever mastered was backgammon - Douglas William Jerrold
A couple years ago, right during the push for the Iraq invasion, I dislocated my shoulder on a train in Northern France(slept on it wrong) and ended up in the E.R. in Nancy-Ville or however the heck it's called. They were sort of amused by my hollering loudly in English ("Americain" one of the guys remarked to his buddy with a chuckle) but my brief stay there dealing with the E.R. doctors and nurses and people around town the next day, they didn't have a huge problem with me being an American who spoke three words of French, and impressed me as being pretty hospitable. Plus, I got a ride to the E.R. in an ambulance, an X-ray, some morphine(weird stuff... you still notice the pain sensations but it doesn't hurt), a relocated shoulder, and a few hours of sleep on a stretcher for, I shit you not, like 100 euros... this would cost easily a couple thousand in the states, without the ambulance ride (I know 'cause I've done this a lot). Socialized medicine, don't knock it till you've tried it.
The USA has sold the farm - innovation is what it has left and weird patent laws are trying to kill that too. Experiments such as this are an investment in the future, so if you are worried about the future of the USA you should be behind such things as this. And stop your management getting hold of hard drugs, that's the only thing that can explain a lot of decisions.
And this is an example of why "America" is no longer great.
:
.....
If you (as a country) spent less time watching "info-mercials" and more time actually learning real history, you would know that Henry Ford is responsible for the introduction of the production line. He didn't invent the car, there were French, German and British inventions way before his car was built.
As for inventing the aeroplane, that is not entirely true either. The wright brothers were credited with the first powered flight, but they built on the work of others in Europe, and there is even some doubt as to whether they were the first to achieve powered flight.
As to the Chrysler/Mercedes Benz thing, you do realise that most of the inventions that "America" is famous for were invented by European immigrants. Names such as Einstein and Werner von Braun spring to mind here.
Add all this to the fact that "American" companies have been taking over the rest of the worlds industries with the almighty dollar for over 40 years and you might realise what the fuss over globalisation is about.
fucking goldfish memory !
Telephone - Alexander Graham Bell - Born in Scotland
Wireless transmission - Guglielmo Marconi - Born in Italy
Manhattan Project - J. Robert Oppenheimer - Born In New York to German Immigrants
Electronic Computer - Konrad Zuse - Born in Germany
Helicopter - SIKORSKY, Igor Ivanovich - Born in Russia
Motorcycle - Gottlieb Daimler - Born in Germany
Bicycle - James Starley - Born in England
Jet airplane - Hans von Ohain - Born in Germany
British
Disc Brakes - Frederick William Lanchester
Tin Can - Peter Durand
Cat Eyes - Percy Shaw
Portland Cement - Joseph Aspdin
Cordite - Sir James Dewar, Sir Frederick Abel
Electric Motor - Michael Faraday
Locomotive - Richard Trevithick
Periscope - Sir Howard Grubb
Polyester - John Rex Whinfield and James Tennant Dickson
Viagra - Peter Dunn, Albert Wood, Dr Nicholas Terrett
Waterproof Fabric - Charles Macintosh
World Wide Web - Tim Berners-Lee