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Comment by madaxe | Hacker News Reader

There probably is a nuclear blast in that mix. They stated that anti-missile systems intercepted it - the only thing with a hope in hell of reaching and destroying/breaking a meteor is the 53T6 Gazelle, which has a 10kt warhead.

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Can someone please enlighten me, because I was under the impression that there is no ABM system on the planet capable of intercepting, let alone destroying, a large rock moving at 10km/second.

I'm not saying its impossible, but it just seems to me that there is a lot of misinformation as to what actually happened.

I'm with you here. The RIM-161 standard anti-ballistic missile used by the US is quoted by wikipedia as having a speed of 9600km/h or 2.7km/s. Speeds in low-Earth orbit are about 7-8 km/s, objects entering from a solar orbit likely several times that. There is absolutely no way you would have significant success probability of intercepting it with a missile unless you knew the incoming orbit very precisely.

Just look at that dashcam footage: from entering the atmosphere to breakup was just a couple of seconds. On a very tangential orbit, no less.

Gazelle does at least 5.5km/s.

But how long does it take to get to that speed?

By the time its left the silo. Russians are dead keen on their one-shot silos packed to the gills with various devices (pneumatic, hydraulic, explosive) to bring a missile up to ludicrous speed very, very quickly.

Spent a very enlightening afternoon down an old bunker near pervomaisk.

Found some stats in the tourist brochure from there. 9.4m high,1.1m dia, 4km/s in 4s, which gives an acceleration if about 102g. 80-100km range. Max speed 7km/s. "directional blast" also, which is interesting.

The US Nike-X Sprint had similar performance (Wikipedia says only 90 gravities, and there's some nonphysical-looking footage of test launches on youtube somewhere). Pretty crazy, and I gather that MIRVs made that whole category of ABM obsolete.

Yup. Aforementioned satan missile can carry hundreds of warheads, and an equal number of decoys. Two of them, they said, could wipe out all US cities.

I'm skeptical there exists a system to automatically fire nukes at something and it has never had a false positive. Especially (chauvinistically) under control of the Russians through the fall of the the USSR.

I'm not sure a terrestrial power could do this without being way visible ahead of time.

I agree with you. Even (not chauvinistacally) under control of the USA, EU, China, Japan, India or Australia.

In a few cases Russian military officers like Stanislav Petrov have ignored protocol, not fired their nukes, and prevented global nuclear war.

http://en.wikipedia.org/wiki/Stanislav_Petrov

I predict the ABM interception will turn out not to have occurred. We don't have a surveillance system capable of detecting something that size until it hits atmosphere, which means there would only be seconds of warning. That's not enough time to make the decision to fire an ABM.

> I predict the ABM interception will turn out not to have occurred.

I agree.

> We don't have a surveillance system capable of detecting something that size until it hits atmosphere,

NASA tracks at least 21,000 items above 10 cm diameter.

Objects above 3 mm can be tracked by ground based radar. (http://orbitaldebris.jsc.nasa.gov/faqs.html#3)

(http://orbitaldebris.jsc.nasa.gov/)

Almost all the items NASA tracks have orbits inside the solar system. This thing came out of nowhere (if it's orbiting around the Sun, it's so excentric that the orbit period is very long so it's like we saw it for the first time - if it's not orbiting the Sun, we did see it for the first time).

The NASA program in question is actually limited to objects in orbit around the Earth. (Orbital Debris is typically out-of-commission satellites and parts of rockets that are still in orbit around the Earth.) We can track objects as small as 10cm that are in orbit around Earth. (schiffern explains in more detail how.)

To track potentially hazardous astroids (PHAs), scientists use different methods and are not capable of detecting rocks as small as this one. That doesn't mean that it came from outside the solar system or that it has an eccentric orbit. It just means that it was too small to detect with current methods.

What's your basis for asserting that it has (well, had) a particularly eccentric orbit?

Size isn't everything. Tracking objects in Earth orbit is much easier. You can combine multiple radar measurements to tease a signal out of the noise floor, and model the orbital mechanics to achieve better spatial resolution than your instrument can actually resolve.

> NASA tracks at least 21,000 items above 10 cm diameter.

How many items does NASA track which are 10 cm - 10m diameter and not orbiting the earth ?

As far as I know the only active ABM system in Russia is around Moscow. Chelyabinsk is not anywhere near the Moscow Oblast.

They've got them peppered through the Urals. Lots of Cold War silos in that neck of the woods, and definitely active ABMs - saw them being driven just outside of astrakhan in the dead of night last year.

Also, kaz is full of Russian military hardware. Baikonur for instance is definitely covered by ABMs, as to not do so would be an untenable risk as far as Russia is concerned.

Are you certain? This would be news to the world.

For reference, here's what an ABM transporter looks like: http://www.ausairpower.net/PVO-S/53T6-SH-08-Gazelle-ABM-TL-1...

Or this: http://www.ausairpower.net/PVO-S/Gorgon-ABM-Transporter-Load...

Here's what a portable ICBM looks like: http://upload.wikimedia.org/wikipedia/commons/0/00/Moscow_Pa...

Or this: http://www.fas.org/programs/ssp/nukes/images/rs24tel.jpg

Yup, those would be the ones. Nice long convoy of them with APCs and tanks at the head and tail, cruising down the highway.

Seeing this kind of stuff is par for the course out there though. Drove from Rostov na donu to Stalingrad and there were huge (and I mean HUGE) convoys of tanks cruising down to syria's neck of the woods.

This isn't news to the world, it's just known stuff that isn't talked about as it doesn't mesh very well with realpolitik.

Edit: think there was also a satan in the convoy we saw, two massive stages on separate carriers. Proper "oh holy shit what am I seeing pretend I'm not here" stuff.

A satan? Can you explain?

SS-18 'Satan' is a NATO designation for Soviet/Russian ICBM. http://en.wikipedia.org/wiki/SS-18

You haven't lived until you've sat on top of one (on its side!) waving a cowboy hat. Fond memories... Although I now also remember my lunch of various animal tubes on the same day. Damnitall.

That's not news :) The reason these things are extremely off-road capable is so they can move around in the woods and the enemy can't take them out in a first strike attack. The retaliation capability is what creates the (desired) balance between nuclear powers. Same with nuclear submarines. Hide and seek for "grown-ups"...

Don't forget "passenger trains". Neatly dressed up to look like the express service, but chock full o' nuclear goodness. The roof peels back, and you can launch straight from the rails.

According to the article, "Servicemembers from the tank brigade that found the crater have confirmed that background radiation levels at the site are normal", and "Background radiation levels in Chelyabinsk remain unchanged, the Emergency Ministry reported".

I am no physicist. But assuming that we can take these reports at face value, doesn't that rule out the possibility that the meteorite was intercepted by a nuclear device?

Not really. A 10kt yield at altitude wouldn't leave much radioactivity above background at ground level.

Also, this is the Russian military we're talking about. I don't think they'll fess up to detonating a nuke, no matter how small, in a populated area.

We're talking about the same guys who absolutely definitely positively did not use nukes to build shipping canals.

Oh, and I am a Physicist. MSc from an Ivy-League equivalent in the UK, although these days I'm a web gimp instead.

We're talking about the same guys who absolutely definitely positively did not use nukes to build shipping canals

Ok, I'm genuinely not sure whether you're being sarcastic. So _did_ the Russians use nukes to build shipping canals?

They experimented with it, publicly declared it a success, but said they weren't going to do it, and proceeded to use the tech on the far side of the country. Pechora-Kama I think was the original project. Maybe they did, maybe they didn't, but the locals I've met (Kazakhstan) insist that they did.

Didn't the US experiment with it as well?

http://en.wikipedia.org/wiki/Operation_Plowshare

It wouldn't surprise me if the Russians were looking at the same thing, but it should leave some fairly telling clues behind. At the very least you can see plowshare craters littering Nevada on google maps (in a nice grid pattern in some areas, just search for "Sedan crater" and zoom out a little), I would expect similar to be somewhere in Russia if they were doing the same.

Edit: This is the Russian version of plowshare: http://en.wikipedia.org/wiki/Nuclear_Explosions_for_the_Nati... http://en.wikipedia.org/wiki/Chagan_(nuclear_test)

A 10kt yield at altitude wouldn't leave a crater, either...

Unless it was used to blow up a large chunk of rock which then proceeded to fall to the ground. In that case, you'd get a crater, but you'd also get the radioactive material.

Depends on how good their equipment was. The small boosted plutonium warheads used in that kind of missiles are extremely clean (they are meant to be used over their own territory, after all...), and I think that after the kind of wide dispersion you get when the surface of the object ablates away as it falls there might not be much more than a small blib over the background left.

However, based on my very limited knowledge, I think that the Russians are supposed to only have operational Gazelles in a ring protecting Moscow, and those shouldn't have the range to hit anywhere near Chelyabinsk.

I don't see any explosions here: http://www.youtube.com/watch?feature=player_embedded&v=i...

You see the explosion. It's just about 150 km north from explosion (over Chelyabinsk, Russia). That video was made from Kamensk-Uralsky, Russia.

https://maps.google.com/maps?q=from:+Russia,+Sverdlovsk+Obla...

Edit: Fixed city name, added map.

That's extraordinarily unlikely.

edit: http://www.nature.com/news/russian-meteor-largest-in-a-centu... "Explosion rivalled nuclear blast, but rock was still too small for advance-warning networks to spot."

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