h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: The Chelyabinsk Superbolide - A87823768
Author: Galaxy Babe - eclectic editor - U128652

For February's Create: Science Fact.

GB

Nice summary of items, Galaxy Babe.

A very good and interesting read.

My only thought was would it be worth mentioning in the conclusion that many people believe that the destruction of the dinosaurs might have been caused by an asteroid strike. Or has that theory been debunked?

How far do you have to go to be safe from a bit of rock

F S

Thanks Elektra

Hi FS, thanks for the review and comments. I've added a bit about the dinosaurs in my conclusion. As to your question "How far do you have to go to be safe from a bit of rock?" In this case it's not the size that matters but the speed - I could hold a bullet in my hand and it would look quite innocuous but if someone fired it at me from a gun it would probably kill me. I must say I wouldn't fancy anyone's chances if that 1.8km-wide asteroid currently near Earth were to hit us, we'd be probably looking at tsunamis, nuclear winter and those who survive living in underground bunkers for many years. Don't fancy that much myself

GB

I always think the most sensible place to be, should the really* distructive big enough one hits, is directly underneath.... the post-apocalyptic 'survival' alternative doesn't sound too great... and I bet there'd be no cheese left

Nice article, read through really easily and nicely; it all flowed and made sense (and I don't know a great deal about rocks in space... as it were )

This is great! Breezy, informative, and beautifully organised. Thanks for cluing us in.

I have only one suggestion to make, and it's a tiny one.

>>as a once-in-a-lifetime event unfurled<<

'Unfurled' sounds like a flag. Could you say 'unfolded'?

You and me both, 2legs

Thanks Dmitriand I've changed that pesky word for you

Thanks! I can't wait to see the illustration for this one.

Excellent! Very enjoyable. I admit I clicked on it to find out what a superbolide is. I remember the incident now, I'm just not good at remembering the names of Russian towns.

I can't suggest an addition to the facts, just a nitpicky sentence structure thing (sorry, my mom was a teacher).

Instead of:
"Those who knew about this event breathed a huge sigh of relief, we dodged a bullet this time. Compared to asteroid 2012 DA14, the Chelyabinsk superbolide was much smaller."

my suggestion would be:
"Those who knew about this event breathed a huge sigh of relief. We dodged a bullet this time, as the Chelyabinsk superbolide was much smaller compared to asteroid 2012 DA14."

All your words are there, just in a different order! Feel free to ignore, I just feel it flows better that way. Your intent is still clear as-written.

Thanks very much!

You're right, that does flow better, I've changed it

GB

This is good, but I think it is confusing by talking about different near earth objects which we encountered on the same day as well as throwing in another from 1 January. I'd like to think about some suggestions for fixing this, but I need to wait until Saturday when I'm back at my computer. I can't do it on the mobile phone.

I think it works, with the mention of the same day objects, and related ones... As it helps put the actual event in context... It didn't seem to confuse it too much in my head, at least, on my reading of it

Thanks 2legs

This is good - if rather scary.

There are a couple of points in the 'Superbolide'section that bothered me. The first was the reference to Apollo class asteroids. Is that what they're called? I can imagine a conspiracy theorist thinking the Americans had crashed one of their space rockets.(Tinfoil hat similey)

The second was the reference to Hiroshima. Perhaps you should add the reason why the superbolide didn't cause that kind of devastation - presumably because the explosion occurred in the earth's atmosphere

Hi mvp

Thanks for your review and comments

The Apollo class asteroids are named after the first one of a certain class, in this case 1862 Apollo, much the same as Cepheid variable stars are named after Delta Cephei A87812274.

I've added the following footnote on "Apollo class":

The asteroid 1862 Apollo was detected by German astronomer Karl Wilhelm Reinmuth (1892-1979) in 1932. Since then, other, similar asteroids on roughly the same track are deemed to belong to an 'Apollo' class, named after the first one.



Both explosions occurred in the Earth's atmosphere. The difference is one was natural, much faster and coming in at an angle. I didn't like comparing the two, it's there for readers to acknowledge the power of nature.

GB

Rather than explaining why they're called Apollo class, I'd say what they are: Apollo class asteroids are ones whose orbit crosses the Earth's and could at some point collide with our planet.

done

Hi GB.

This was an exciting event, and your entry certainly captures the excitement. I feel, though, that it jumps around from topic to topic without fully explaining things. Most of the topics in it are familiar to you, but I don't think they are completely obvious to a casual reader.

I think you need to state clearly that the superbolide was a lump of rock that was heated up by friction with the Earth's atmosphere to the point that it exploded while it was still high above the Earth. What altitude was it when it exploded?

You talk about the value of meteorites, but you don't explain what a meteorite is. I think a sentence or two at the start of the meteorite hunt section would help, for example:

A meteorite is a piece of space rock that makes it as far as the ground. When the superbolide exploded, much of it was vaporised, but hopes were high that large chunks of it might be found scattered around Chelyabinsk.

Other things that I think need attention:

You say that fragments of the meteorite were minted into medals - "minted" is normally used for making metal coins. Were the meteorite fragments made of metal? I know that some meteorites are made of metal, but you've talked about a lump of rock up to this point.

You talk about 2012DA14 with a subscript 14, but every other report about this asteroid does not use a subscript. Can you check this, please?

I think this bit could be better phrased, and could have a little extra information, too:

"Those who knew about this event breathed a huge sigh of relief. We dodged a bullet this time, as the Chelyabinsk superbolide was much smaller compared to asteroid 2012 DA14."

I suggest:
"Those who knew about this event breathed a huge sigh of relief. We dodged a bullet this time, as asteroid 2012DA14 is much bigger than the Chelyabinsk superbolide, and would do correspondingly more damage. Astronomers knew that it would not collide with the Earth this time round, but it was still good to see it receding into the distance."

I'm still slightly troubled by the first and last paragraphs of the entry, but I haven't yet thought of a better way of phrasing them, so I'm not suggesting any changes to them at the moment.