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Asteroid to Make Closest Recorded Pass to Earth
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."
Section of an IAU Statement prepared by Dr. David Morrison, 14 March 1998
The International Astronomical Union's (http://www.intastun.org/) list of 108 known ''potentially hazardous objects,'' or PHOs.
Most of the asteroids that could strike the Earth and cause a global catastrophe have not yet been found. For the year 2028 (or any other year) the chances of an unknown asteroid hitting the Earth are much greater than the chances of this particular asteroid hitting. If an unknown asteroid should hit us, we would likely have no warning at all. The first we would know of the danger is when we saw the flash of light and felt the ground shake. At the current rate of discovery, it will take more than a century to find 90% or more of the objects this large with Earth-crossing orbits. For better or for worse, the astronomers who carry out these searches and orbit calculations work in the public eye. The idea that a threatening asteroid could be kept secret (or that anyone would want to keep it secret) is ludicrous.
For further information see the NASA asteroid and comet impact hazard website at:
For a long list of Potentially Hazardous Asteroids (PHAs) see: http://cfa-www.harvard.edu/iau/lists/PHACloseApp.h tml
Also, for information on assessment of the
impact risks using the Torino Scale, which is
kinda like the Richter Scale for impact risk,
see: http://neo.jpl.nasa.gov/risk/
A 100-ft diameter asteroid will make the closest (26,500 miles, or about 3.4 Earth diameters)
If "feet" or "earth diameters" are not your preferred units of measurement, what the article is trying to say is that the asteroid is about 90m in diameter and will pass the earth at a distance of about 42600 km.
)9TSS
100' diameter ==> 15m radius ==> around 15000 m^3 ==> somewhere around 5x10^7 kg if it's rock.
:)
26500 miles is around 4000 times further away from the surface of the earth than the 35,000 feet at which planes fly.
So the gravitational effect this rock will have at the surface of the earth is around the same as the effect from a 3kg bag inside a plane flying overhead. Probably not noticable.
Tarsnap: Online backups for the truly paranoid
But Skylab wasn't going as fast - Celestial mechanics isn't my strong point, but something falling from a gradully-decaying orbit around the Eath (eg Skylab) won't be going half as fast relative to the Earth as something aproaching perihelion on a huge elliptic orbit round the sun (eg an asteroid) - things on elliptic orbits go faster the closer they get to the thing they're orbiting. Conservation of angular momentum or something.
And as Skylab wasn't going as fast, it wasn't heated up so much in the atmosphere, so more bits of it reached the surface than most meteorites.
evil math within Nature's Cubic Creation!
Mod the parent back down. The AC which already replied and was marked as flambait is right. This guy is an idiot. The only exception where his statement might hold water would be if the object were solid water...and then, maybe. And then, it wouldn't be because of "pressure differences", it would be because of super heating, causing steam to form inside, causing it to explode.
The meteor that made Barringer Crater in Arizona (1.6k across and nearly 200m deep) was ~45m in diameter -- only about 50% wider and roughly twice the mass of the one detected. This rock _could_ have spoiled someone's day....
Got mead?
From what I am reading in the articles on the net, 100 feet can still create some serious, albeit localized damage. If this bad boy were to hit over the ocean, probably not much, but over land, it could cause serious local destruction. Anyone out there serious about their astronomy?
The Tunguska Blast over Siberia was an object about 100 meters in diameter. Sure it burned up in the atmosphere, but it was devastating to the ground anyway. This article also mentions that at about 50 meters, these rocks make it through the atmosphere and can do serious localized damage. So, since 100 feet converts to is 30.48 meters, this rock would more than likely to have an effect that we will notice on the ground.
For further reading, here is a site that has already compiled links and information And, of course, the Yahoo listings on Earth Impact information online.
InnerWeb
Freud might say that Intelligent Design is religion's ID.
An 80ft asteroid caused Meteor Crater at 1.2km wide. A 100ft one may likewise not burn up. Meteor Crater
Plug in some numbers and find out :)
copper
Taken from the following NASA article.
East Coast Brewers
Back in my Army SSDC days our main geosynchronous comms satellites were on a 22,300 mile orbit. This thing is going to pass just above. Suddenly these 26,500 miles don't look *that* far to me.
Pedro
----
The Insomniac Coder
I may be reading the impact risk table wrong, but right now it seems to say that the distance it will miss by on Jan 12, 2053 is .01 earth radius. I assume that this means that we are very near the center of the area of uncertainty about where it will impact, and that the areo of uncertainty is currently extremely large.
On the other hand, I seem to recall that most previous predicted near misses had us further out from the centroid, and as the orbital data was refined, the area of uncertainty shrank until we were no longer in it. I suspect that reducing the uncertainty without changing the orbital prediction would raise the calculated risk with time.
As I read it the impact energy would be about equal to a 300Kiloton bomb. Not a particularly large hazard area if it came straight down (it probably won't), but it would certainly be big enough to mess up somebody's day. For that matter, has anyone actually run a prediction of what the effects (thermal, weather, etc.) would be from a grazing strike where it travelled parallel to the surface for a long way before breaking up or leaving the atmosphere?
Liquor
Sanity is a highly overrated commodity.
50% wider and roughly twice the mass of the one detected
;-)
If both bodies were the same shape the larger would have eight times the volume.
Er, 1.5^3 = 3.375, not eight. Other than that you're doing fine
-- Alastair