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."
Huh? (Score:3, Interesting)
The Death Star was bigger than 100 ft dia! Maybe the miniature Lucas used was that size?
Lucky (Score:5, Interesting)
It *will* give them a chance to study the thing as it passes, since all the other ones were only detected after they'd gone (and presumably therefore couldn't be easily studied). If it's close enough to see with binoculars, it ought to be possible to resolve quite well in a good optical 'scope.
The other point I guess is that it's only 100 ft across (why not 30m ?) so it would have burnt up on entry into the atmosphere, but still, good to know about these things. An asteroid that big would make quite some bang on entering the atmosphere, I reckon
Simon
Re:Lucky (Score:4, Interesting)
But you do bring up a good point - if this object would have hit Earth, would it have burnt up, or would something dangerous remain?
Much smaller items hit Earth all the time - they don't get burnt up completely. Of course, many end up the size of maybe pebbles or baseballs...
And if... (Score:5, Interesting)
I highly doubt we will be told about it. Instead, our world leaders will gather in a cave somewhere with their mistresses and 500 years worth of refried beans...that ought to keep the human race going.
-Grump
Re:Lucky (Score:5, Interesting)
This one is flying pretty darn close for comfort.
Gravitational Effects? (Score:5, Interesting)
Hmm (Score:5, Interesting)
Sort of puts our achievements into perspective...
Re:Lucky (Score:1, Interesting)
You get really big fireworks.
Jeroen
Re:Lucky (Score:3, Interesting)
I imagine that if it were a roughly spherical, dense, metallic object it would have a good chance of hitting the surface.
also to be noted (Score:2, Interesting)
THE SAGA OF ASTEROID AL00667 = 2004 AS1
Brian G. Marsden (from CCNet, 15 January 2004)
"That this latest PHA should have generated so much heated discussion on numerous mailing lists and the internet on the basis of four observations covering a time interval of one hour on the morning of Jan. 13 is surely quite amazing. On the routine arrival of the night's LINEAR data at the Minor Planet Center at 5:15 p.m. EST that day, the usual computations on them were quickly done, and, within a matter of minutes, five of the objects were placed on the MPC's WWW "NEO Confirmation Page" as being of potential NEO interest, predictions of the expected positions and their uncertainties being provided in the hope of securing early confirmation from observers in Europe. It was evidently cloudy over most of the continent, however, and the only follow-up observations immediately forthcoming were in fact from a single observer in the U.K. Also according to usual procedures, on the receipt of these U.K. observations, the predictions on the WWW could be quickly and significantly refined, well in time for further observations to be presumably made from North America. There was in fact also rather extensive cloud cover that night over North America, particularly over the numerous professional and amateur observatories in the frequently blessed Southwest.
Re:Lucky (Score:3, Interesting)
For those too lazy to click the link, this is the relevent quote from the press release.
Re:NASA's on the job. Can they save the world? (Score:2, Interesting)
Re:Huh? (Score:4, Interesting)
My biggest fear is that we will be hit by a not-quite planetkiller that will cause enough devastation to ensure the survivors live in misery for the rest of their (short) lives. That would suck.
Re:The big one... (Score:3, Interesting)
Talk about the ultimate episode of survivor.
Re:How far away? (Score:3, Interesting)
So, a question for the astronomers (Score:3, Interesting)
I'd hate to be a (Score:5, Interesting)
Re:Lucky (Score:3, Interesting)
Little objects like a grapefruit weren't a hundred feet wide. A hundred foot wide ball or potato-shaped rock could break up and would rain down millions of grapefruits at n miles/sec., if it broke up at all. Think of a hundred thousand ton blast of buckshot at 5 miles/sec. Or a 100K ton cannonball at the same speed.
Big mess.
Re:How far away? (Score:3, Interesting)
Any object approaching from angles significantly above or below the equator will have only a very small chance of nailing a geostationary satellite.
Re:Lucky (Score:5, Interesting)
No he's not.
It depends if it solid rock. many stony asteroids are apparently spongy having once contained volatiles that have subsequently been lost to space. These fragile objects will disintegrate in the atmosphere as atmospheric deceleration crushes them.
Its for this reason that carbonaceous chondrite meteorites - the black ones with the exciting organic compounds are relatively rarer on Earth than their abundance in space would suggest. We're regularly encountering them, they just don't make it through to the surface.
Having said that a 25m chunk of anything disintigrating in the atmosphere would produce a blast in the high kiloton, low megaton range. One of these smashing into a city would be a catastrophe.
And they seem to be more common than we think - there is obviously Tunguska in 1908, but then there are reports of something exploding over the Amazon basin in the 1930s, the more than 100 small impacts that hit Sikhote-Alin in Russia in 1947 and the most recently uncovered biggish impact at Wabar in Saudi Arabia - a Hiroshima-sized explosion in either 1863 or 1891 (there is no agreement on the date, since Arabic scholars saw two bright meteors heading in that direction on different dates, it's only recently that scientists have been able to determine the relative youth of the Wabar craters).
Best wishes,
Mike.
Re:Lucky (Score:2, Interesting)
Also, wouldn't these smaller parts have the potential to have a much slower terminal velocity? Sure, it might not have time to slow down to terminal velocity speeds, but you never know.
Of course, it all depends on where it breaks up. If it's a loosely enough packed ball of rubble, the gravity of earth may break it up before it even reaches our atmosphere. Also, depending on where it breaks up, parts may go into the ocean that would have landed on land and vice versa.
BTW, I have absolutely no idea if what I'm saying is in any way based on fact or even following any form of logic.
Re:Lucky (Score:5, Interesting)
And shock waves aren't sound, so they can move quite quickly. The air itself would be moving at hypersonic speeds, mixed with vaporized solid matter from ground zero. Dust, really fast dust, and gravel.
We came pretty close. (Score:5, Interesting)
So basically, to avoid a direct hit, the the timing of of a near-earth-asteroid only needs to be altered by 6 minutes over the course of its orbit(s).
What I can't get over is that we *missed* this asteroid by only 12 to 18 minutes!
That's just crazy.
Re:100 ft may seem small, but .... (Score:3, Interesting)
Now, we don't know much about this object's composition, so it could be iron. If so, and if it were moving a bit faster (30 km/s), this is what we get:
If the iron version hit the ocean, it'd create quite a significant tsunami - though not a catastrophic one unless it hit near the shore.
From the book of Revelation: (Score:2, Interesting)
Rev 8:10 And the third angel sounded, and there fell a great star from heaven, burning as it were a lamp, and it fell upon the third part of the rivers, and upon the fountains of waters;
Rev 8:11 And the name of the star is called Wormwood: and the third part of the waters became wormwood; and many men died of the waters, because they were made bitter.
Rev 8:12 And the fourth angel sounded, and the third part of the sun was smitten, and the third part of the moon, and the third part of the stars; so as the third part of them was darkened, and the day shone not for a third part of it, and the night likewise.
Now just hope they don't name some asteroid "Wormwood".
Crushing it to small pieces won't help. (Score:3, Interesting)
"Oh - we'll blow it up. That'll make it go away."
Wrong. Mass and inertia are mass and inertia. The results might be a bit different - a dense solid object will tend to penetrate the surface a bbit deeper, but the heat generated from a billion tons of sand travelling 14 miles a second would instantly superheat the atmosphere, and the impact on the earth would be incredibley destructive - the silicon, magnesium, sodium, etc. in the stuff isn't going to disappear, and the associated mass has to transfer its inertia into some other form of energy, and a billion tons of inertia is a billion tons of inertia.
The best thing to do is to a solid chunk is to deflect it. If the asteroid is solid metal and valuable metal at that, it might be a good idea to dump it on the moon or Mars, where the metal can be used to make buildings and space craft.
Otherwise, pitch the sucker into the sun. Or Venus. Or someplace else. In fact dumping it into Venus might be cool - see what kind of wreckage develops...
Now, if it's a loose piece of crap, like a semi-shattered dead comet, that would*suck* because deflecting something like that would be pretty difficult. A billion tons of ice and gravel is still a billion tons of ice and gravel.
RS