NASA Says Asteroid Will Buzz Earth Closer Than Many Satellites 225
coondoggie writes "NASA says an asteroid about half the size of a football field will blow past Earth on Feb 15 closer than many man-made satellites. NASA added that while the asteroid, designated 2012 DA14, has no chance of striking Earth. Since regular sky surveys began in the 1990s, astronomers have never seen an object so big come so close to our planet."
Re:Yeah, about that... (Score:3, Informative)
Why would a change in mass change the trajectory? Granted, it was a while since I took physics, but from what I remember:
1. The force of gravity follows F = GMm / (r^2) where M and m are the masses of the two objects in consideration. Here I will use m as the mass of the asteroid and M as the mass of any other object that is not the asteroid.
2. F = ma.
3. From this follows that a = (GMm / (r^2)) / m = GM / (r^2). As we can see, m (the mass of the asteroid)
This means means that the accelleration of an object due to gravity is only affected directly by the other object's mass, not by the object's own mass. However, a more massive object *could* attract other objects with a higher accelleration than expected, thus reducing r, thus over time increasing the accelleration, changing the tracjectory of not only the asteroid but also the other object.
Consider for a moment, however, how insignificant such an effect would be:
First imagine an asteroid the size of a football field. Then imagine the moon. Then imagine the earth. Then imagine the sun. Now imagine the mass of an asteroid even moving the moon more than an imperceptible amount due to gravity, let alone the sun.
Cite the NASA story, not some parasite's blog (Score:5, Informative)
Why source a story sourced from NASA to some wanker's blog in Network World"?Presuambly this asshole just submitted it himself to get more pageviews.
The actual NASA story is Record Setting Asteroid Flyby [nasa.gov] And it actually tells you that "On Feb. 15th an asteroid about half the size of a football field will fly past Earth only 17,200 miles above our planet's surface." (Sadly even NASA use the inane "football field" measure, but goes on to say "It measures some 50 meters wide".)
Re:Call Bruce Lee (Score:5, Informative)
http://www.imdb.com/name/nm0001569/bio [imdb.com]
"He is a black belt in Tang Soo Do and Tae Kwan Do. In 1969, he earned the Triple Crown for the highest number of tournament wins, and was named Fighter of the Year by "Black Belt" magazine. By the time he was 34, Norris had established 32 karate schools and had been a champion for six years. In 1996, he became the first Westerner to be awarded an eighth-degree black belt in Tae Kwan Do"
I am not a big fan of this guy, and i agree these Chuck Norris jokes are very annoying, however, facts are facts and clearly you are wrong about the martial arts.
Re:Is there a chance of it hitting a satellite? (Score:5, Informative)
Well, geostationary orbit is about 250,000 km in circumference, and it contains about 400 satellites at present. Assuming they're each 50m wide (which is probably an exaggeration) then the satellites, in total, cover 20km of that circumference. So if we were to assume that all the satellites are in the same plane, and that the asteroid was definitely going to come in through that plane, then the chances of the asteroid meeting one of those satellites is 0.008%.
A back of the envelope calculation suggests you have the same odds of spinning around in a circle with your eyes shut and successfully pointing at a person standing 3km away.
Re:Yeah, about that... (Score:4, Informative)
The trouble is that what happened to Shoemaker Levy 9 doesn't scale down: it was ripped apart by the tidal forces of a gas giant, and those forces don't exist for a similar size of body interacting with Earth.
Re:Call Bruce Lee (Score:4, Informative)
As someone who studied Kempo many many moons ago, I wholly agree with Bruce's outlook. What I was taught was extremely rigid, canned moves that might work if you were extremely lucky enough for an attacker to come at you in precisely the manner they trained you for, but if they deviated at all, if all you had to rely on were the moves you were taught (and you couldn't improvise on your own), you'd be toast. Though I'm not sure if this reflects more on Kempo itself, or the school I attended.
Though this leads me to wonder why we have this prevalent Chuck Norris meme, but not one for Bruce Lee?