Dakoda Posted October 10, 2001 #1 Share Posted October 10, 2001 The most dangerous asteroids, capable of a global disaster, are extremely rare. The threshold size is believed to be 1/2 to 1 km. The threshold for an impact that causes widespread global mortality and threatens civilization almost certainly lies between about 0.5 and 5 km diameter, perhaps near 2 km. But can we predict a hazard of such in the near future? And if so, what sort of impacts are we looking at???. Link to comment Share on other sites More sharing options...
Tommy Posted October 10, 2001 #2 Share Posted October 10, 2001 Hey Dakoda, :se Interesting topic. Check out the Impact Hazards, Possible Life Extinction section towards the bottom of this link… http://members.aol.com/gca7sky/planets/meteors.htm :s1 It provides many useful links with information on these “Potentially Hazardous Asteroids, or ‘PHA’ as the NASA Near Earth Object Program calls them. http://neo.jpl.nasa.gov/index.html Enjoy Tommy Link to comment Share on other sites More sharing options...
Dakoda Posted October 10, 2001 Author #3 Share Posted October 10, 2001 Thanx a bunch Tommy Link to comment Share on other sites More sharing options...
Homer Posted October 10, 2001 #4 Share Posted October 10, 2001 According to scientists at NASA's Jet Propulsion Laboratory, there are currently 315 known "potentially hazardous asteroids," or PHAs. Each appears to be on a course that will one day bring it close to Earth's orbit, but scientists stress that none of them are known to be on a collision course with the planet. Many other asteroids that might be listed as PHAs are thought to be out there but not yet found, reflecting the fact that researchers don't know how many asteroids are out there, let alone how many might eventually cross the path of Earth. Homer[glow=color,strength,width] Link to comment Share on other sites More sharing options...
Mystify Posted October 10, 2001 #5 Share Posted October 10, 2001 If an asteriod were travelling at the speed of light or somewhere in the vicinity, could we detect something like this before it is too late? Link to comment Share on other sites More sharing options...
Homer Posted October 11, 2001 #6 Share Posted October 11, 2001 Mystify, When you want to discuss a fast asteroid, you don't fool around.;D According to Special Relativity(E=mc^2), the "relavistic mass" of an object increases as its speed increases and approaches infinity as the object's speed approaches the speed of light. This means that it would take an infinite amount of energy and an infinate amount of time to accelerate an object with mass to the speed of light. Homer[glow=color,strength,width] Link to comment Share on other sites More sharing options...
Tommy Posted March 20, 2002 #7 Share Posted March 20, 2002 Another asteroid nearly takes us by surprise, by cleverly travelling through an astronomical blind spot. :s8 http://europe.cnn.com/2002/TECH/space/03/19/asteroid.blindside/index.html Link to comment Share on other sites More sharing options...
Homer Posted March 20, 2002 #8 Share Posted March 20, 2002 Stupid Sun ;D Link to comment Share on other sites More sharing options...
PurpleStuart Posted March 20, 2002 #9 Share Posted March 20, 2002 I s'pose we should be pleased that it has awakened people to the possibility that an asteroid could be hidden by sunlight... Link to comment Share on other sites More sharing options...
SpaceyKC Posted March 20, 2002 #10 Share Posted March 20, 2002 Sure was nice of them to 'send us a memo' (after the fact!). :s9 Link to comment Share on other sites More sharing options...
Homer Posted March 20, 2002 #11 Share Posted March 20, 2002 Funding is already very low with trying to locate asteroids we CAN see, and now we have to concern ourselves with the 'hidden ones' as well. What a nightmare. Link to comment Share on other sites More sharing options...
Sheff_Pud Posted March 21, 2002 #12 Share Posted March 21, 2002 We just have to hope they land at night then-to be safe. :s01 Link to comment Share on other sites More sharing options...
PurpleStuart Posted March 21, 2002 #13 Share Posted March 21, 2002 :s2 :s2 :s2 :s2 :s2 *falls off chair* Link to comment Share on other sites More sharing options...
NessyK Posted March 21, 2002 #14 Share Posted March 21, 2002 :s8 OK, which one of you watched Armageddon last night on TV?!! :s2 Link to comment Share on other sites More sharing options...
Magikman Posted March 21, 2002 #15 Share Posted March 21, 2002 This news is atleast a little bit reassuring, considering the inattention and lack of funding previously given the threat in the past; http://www.space.com/scienceastronomy/solarsystem/asteroid_sentry_020314.html Magikman :sg Link to comment Share on other sites More sharing options...
SpaceyKC Posted March 21, 2002 #16 Share Posted March 21, 2002 There are a lot of ignorant people (with money and power), who think that space exploration, etc., is all a huge waste of money - better used for mankind here on earth. So, hopefully, since this is for the benefit of mankind, NASA will finally get more support. : Link to comment Share on other sites More sharing options...
odinsupreme Posted March 21, 2002 #17 Share Posted March 21, 2002 Today I read in the paper that an Asteroid passed Earth 1.5 times the lenght from Earth to the moon. The Asteroid was 100 meters in Diameter. The Problem is that they saw it this week.. two weaks after it passed by. This is another proof of how few we know about the wherabouts of those things. Odin S. :s9 Link to comment Share on other sites More sharing options...
Tommy Posted March 21, 2002 #18 Share Posted March 21, 2002 Odin, that sounds very similar to the asteroid featured in the link I posted. But they say that it was 1.2 times the distance to the moon, and 70m in length. :s8 Tommy :sh Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2002 #19 Share Posted March 21, 2002 Odin, The asteroid passed Earth on March 8th and was discovered 4 days later on March 12th Tommy, They are the same(as I know you already know). Some articles have it at 70m, some say between 50-100m....some say 1.5 and some say 1.2...what are you gonna do, and who are going to believe Link to comment Share on other sites More sharing options...
GIZZIE Posted March 21, 2002 #20 Share Posted March 21, 2002 Homer Your last reply brings me nicely on to my reply: You can predict whatever want - whether you predict correctly is another matter. As seen by the inaccurate reporting (not even predicting) on the asteroid. :s02 Link to comment Share on other sites More sharing options...
Mystify Posted March 21, 2002 #21 Share Posted March 21, 2002 Now as I`ve mentioned before the scary part about this is that one day, without notice, we (planet earth) Could be wiped out be a asteroid within miutes due to the fact it was travelling to fast for us to see or what ever reason it is they missed the last one.... KInd of sucks :s07 Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2002 #22 Share Posted March 21, 2002 Gizzie, The dates were the same as well as the approximate size and distance. Who wants to be the one to go up and accurately measure it? I feel the news is too important to await the "final" decision on the approximate size and distance. Link to comment Share on other sites More sharing options...
Tommy Posted March 21, 2002 #23 Share Posted March 21, 2002 Well one guy thinks he can solve the problem... :s02 http://www.newscientist.com/news/news.jsp?id=ns99991924 Tommy :sj Link to comment Share on other sites More sharing options...
GIZZIE Posted March 21, 2002 #24 Share Posted March 21, 2002 Homer Let's just say it's a BIG one ok? :s2 Link to comment Share on other sites More sharing options...
Homer Posted March 21, 2002 #25 Share Posted March 21, 2002 That's a deal. Big one it is, Gizzie Link to comment Share on other sites More sharing options...
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