Asteroid to Make Closest Recorded Pass to Earth 455
unassimilatible writes "A 100-ft diameter asteroid will make the closest (26,500 miles, or about 3.4 Earth diameters) pass of earth ever detected in advance today, NASA reports. Asteroid 2004 FH's point of closest approach with the Earth will be over the South Atlantic Ocean. Using a good pair of binoculars, the object will be bright enough to be seen during this close approach from areas of Europe, Asia and most of the Southern Hemisphere. While we are in no danger this time, it is good to know NASA's LINEAR guys are on the job, for when that Death Star-sized object pays us a visit."
Re:Huh? (Score:2, Insightful)
Oh Great... (Score:2, Insightful)
Re:The big one... (Score:5, Insightful)
We're all going to die eventually. But throughout all of history, mankind has yearned for the day when we all get to die at the same time. It's not as scary as dying alone, or as scary as the thought the world will go on without us.
Re:NASA's on the job. Can they save the world? (Score:3, Insightful)
Distributed computing? (Score:5, Insightful)
Re:Gravitational Effects? (Score:3, Insightful)
The real threat of these small ones (Score:5, Insightful)
Imagine now that this penetrated the atmosphere over, say, North Korea, or the Sea of Japan, or somewhere over India/Pakistan. It is not much of a stretch to suggest that this might precipitate a limited nuclear exchange. Not a for-sure, but enough of a "could-be" that somebody's day could be ruined.
This is why it is important to look for (small) potentially hazardous objects - not because they will (directly) cause the extinction of the human race, but because they could precipitate an all-too-human conflict, just out of ignorance.
Note also that, as good a job as LINEAR and others do, there is a class of asteroids that are damn hard to see form the ground - the "Aten"-class asteroids, which orbit mostly inside earths orbit and thus come at us from out of the sun. These ones also need to be catalogued and a watchfull eye kept out for.
So, when people start to ask the value of asteroid hunting, bring up these ideas. Sadly, nuclear war is a much more real threat to most people compared to mass extinction.
Re:How far away? (Score:1, Insightful)
And that's exactly why NASA has lost so many Mars probes: the Imperial System
1 in = 25.4 mm
1 ft = 12 in
1 yd = 3 ft
1 fm = 2 yd
1 rod = 5 1/2 yds
1 chain = 4 rod
1 fur = 10 chain
1 mile = 8 fur
I.E. 100 ft = 30.48 m and 26500 miles is, quite correclty, roughly 42600 (42638.5) km.
3 earth diameters.. that's close enough to .. (Score:2, Insightful)
Re:The big one... (Score:5, Insightful)
Hmm, except that this one was detected Monday [space.com]. 3 days notice isn't enough to do anything. Larger ones should be detected earlier but how much earlier?
Re:And if... (Score:5, Insightful)
Re:Gravitational Effects? (Score:3, Insightful)
Tides are caused by the gravitational effect of the sun and the moon on the whole surface of the earth, not on a single point. Let's assume a flat distribution of water on earth's surface. Gauss says that the gravitational force applied to a sphere is equal to the force applied to the same mass positioned at the center of the sphere.
Now, the relevant comparison would be to estimate the relative gravitational effect of our asteroid and the sun. Mass(A)=5x10^7kg, Distance(A)=5x10^7m, Mass(S)=2x10^20kg, Distance(S)=1.5x10^11m. The sun's gravity field on earth is 1,600 times higher than our asteroid's.
So yes, the asteroid will have a negligible effect on earth's surface but not THAT negligible and not for the same reason. Using your logic, my mother (200kg) would have a higher gravitational impact on earth's surface than the sun provided she hovers less than 150m above the surface. Ok, she's fat but not THAT fat
Re:Lucky (Score:5, Insightful)
If both bodies were the same shape the larger would have eight times the volume.
As for mass, Barringer was definitely iron which makes it comparitively rare - less than 6% of observed meteorite falls are iron, yet they make up over 80% of collected meteorites. The latter number is easy to explain - iron meteorites don't look anything like rocks found on Earth, the much more common stony meteorites (which form over 80% of all observed falls) are very hard to distinguish from the stuff on the ground.
More than likely this is a stony body which would give it a much lower density - round about 3.6 gcm-3 as opposed to 7.9 gcm-3 in iron meteorites.
Having said that - a lump of stone that size hitting the Earth would still be comparable to a hydrogen bomb going off - as you say it would have spoiled a whole lot of people's days.
Best wishes,
Mike.
Re:Training material? (Score:3, Insightful)
Hell, we don't even have a booster that could get people to the moon anymore, and even if we still had operational Saturn V's, they still wouldn't boost enough mass out of Earth's gravity well to move a rock that big.
If we had a moon base (far shallower gravity well), and had big ass boosters there (which we wouldn't; why would we have such a thing?) AND we detected an impactor several YEARS early, we might be able to do something. But if we have a significant impactor in the next 100 years or so, we're pretty much fsck'd. Just have your wild party and watch the shock wave come at you at the end.