No Way wrote:
Wow...
First, yes you can shoot a nuclear missle at the sun. It wouldn't even really be hard. It would never make it. You would never see it. If you were to try to look for the explosion you would go blind from staring at the sun. Besides all the other garbage that was posted, the biggest thing is that you couldn't even see it. Its too far away and the sun is too bright.
Quite true. But it could be made a little less difficult to see it if a detonation were to occur near the limb, as seen from Earth
No Way wrote:
Second, there's alot of nonsense posted about how to get it to the sun. Someone spewed some nonsense about finding an "orbit" that "intersects" the sun, and was then backed up by someone of equal (lack of) knowledge. If it intersects with the sun, its not an orbit by deffinition. All you have to do is get the thing far enough from earth so that its not greatly affected by its gravity. Next, point it at the sun and hit the gas. As long as it doesn't come across any other objects, nothing is going to stop it from hitting the sun. Someone correctly cited Newton's laws of motion earlier. Thats true, get it moving, and it won't stop. Things don't just randomly start orbiting stars.
Close, but not quite. Since the nuke, being on the Earth, is already orbiting a star, as pjb noted, you MUST deal with that velocity vector if you want to get to the Sun. If you get far away from the Earth, and then "point it at the sun and hit the gas," you miss by millions of miles. Your plan will work only if you come to a complete stop, which would involve counter-acting the 30 km/s orbital velocity of the Earth. We do not have the technology to do this easily.
No Way wrote:
Third, to the person concerned about destroying the moon with a missle is really overestimating the power of a nuclear weapon. The largest bomb ever made was detonated on earth and barely had an impact on the planet. You see those craters on the moon? If that much energy didn't affect it, we're not going to any time soon.
Also correct. We're not even certain we can destroy a small asteroid with a nuke, much less the Moon which is more than 100 times more massive than the largest asteroid.
Educated Observer wrote:
It would at least knock it off track a bit, enough to mess up the tides. A 200 Megaton bomb would, which is totally possible by today's standards of bomb building.
All a change in the Moon's orbit will do is change the timing of the tides, and possibly their magnitude. And neither of these will have much of an effect on the global oceanic circulation.
Djork wrote:These two idiots have the same IP adress. How pathetic.
Actually, that just means that it is likely that we have the same ISP. And since most astronomers live in only a handful of cities/regions, we could well live in the same region. Although I do not know who pjb is here, it is not entirely unlikely that I might have met him IRL.
No Way wrote:I'm a biologist, not a physicist, but doing some quick (maybe wrong) calculations led me to believe that it would take 7.347x10^18 joules to accelerate the moon 0.01 meters per second.
Fair enough, Dr. McCoy: I'd probably be just as much out of my element as you appear to be if we were discussing what would happen if you fired a person at the moon, rather than a nuke. You are right that it would take a ridiculous amount of energy to change the Moon's orbital speed by 0.01 m/s; but it is even harder than your calculations indicated. My back of the envelope calculations indicate that it would take 7x10^23 J, and the Moon would move about 300km (its current orbit is 400,000 km).
I've had a number of fascinating conversations with astrobiologists (applications of biology to conditions on other planets, and their implications). You must have some interest in astronomy to have been drawn into this thread: if you live near one of the member institutions of NASA's Astrobiology Institute, you might be interested in sitting in on some of their colloquia and/or public talks.
But back to the original question: the idea of sending trash to the Sun comes up often in discussions of nuclear power. The argument is that you fill up a rocket with spent nuclear fuel and "dump" it into the Sun. It is not feasible for two reasons. One is the risk of rocket failure before it leaves our atmosphere, the second is that it is prohibitively expensive to load a rocket with enough fuel to cause it to bleed off all of Earth's orbital velocity in order to hit the sun. In case anyone is still listening: Google NASA's Messenger mission to discover how difficult (and why) it is to get a spacecraft into orbit around the planet Mercury, let alone the Sun.