First Evidence Found of a Comet Strike On Earth

mdsolar writes in with a story about evidence of a comet explosion over Egypt 28 million years ago. "Saharan glass and a brooch belonging to King Tut provide the first evidence of a comet directly impacting Earth, a new study claims. The finding may help unlock some of the mysteries surrounding the birth of our solar system. About 28 million years ago a comet exploded over Egypt, creating a 3600F (2000C) blast wave that spread out over the desert below. The fiery shockwave melted the sand, forming copious amounts of yellow silica glass scattered over 2,300 square miles (6,000 square kilometers) of the Sahara. Polished into the shape of a scarab beetle, a large piece of this glass found its way into a brooch owned by the famed Egyptian boy king Tutankhamen. 'Because there is no sign of an impact crater, it has been a mystery as to what kind of celestial event actually could have caused this debris field, but a small, black stone found lying in the middle of the glass area caught our attention,' said study co-author David Block, an astronomer at Wits University in Johannesburg, South Africa."

Comments

Not necessarily.

[C0R1D4N]

Tunguska is believed by some to be a comet not an asteroid, and since this is hardly confirmed, this is therefore the second "possible comet strike" recorded.

Re:Not necessarily.

[C0R1D4N]

Maybe it will hit a joint session of congress.

Re:Not necessarily.

[Redmancometh]

I bet that would make a good game.

Re:Not necessarily.

[Kethinov]

We didn't get lucky. The vast majority of the surface of the Earth is either not populated or extremely sparsely populated. The odds are strongly against such a large airburst happening to burst over any reasonably densely populated area.

Re:Not necessarily.

[K. S. Kyosuke]

I wonder if the next large airburst like that will hit a city.

You don't have to wonder, I think that maps and probability theory ought to serve you well. As in, we're not in the Trantor stage yet.

Re:Not necessarily.

[MaskedSlacker]

Do you mean an airburst over a city like this ?

Update?

[Dunbal]

'Because there is no sign of an impact crater, it has been a mystery as to what kind of celestial event actually could have caused this debris field'

Are these people dim-witted? We had firsthand video footage of what happens when a big chunk of rock burns into the atmosphere. You get a huge multi-megaton blast like in Chelyabinsk as the meteorite breaks apart due to wanting to move faster through the atmosphere than the air can actually move out of the way... This blast IS NOT NECESSARILY THE IMPACT SITE. It would be a rare thing for a meteorite to be headed perpendicular to the earth's surface. Extrapolating this mechanism to even larger chunks of rock, you'd expect fused sand and little lumps of meteorite, but you wouldn't expect to see the main part of the meteorite where the sand is. That thing landed far away from the blast site. Same for Tunguska - they never found anything because the "crater" is the epicenter of the shock wave, not the actual impact with the ground. All these theories of mysterious "evaporating comets" should be re-evaluated in the face of this new, modern evidence.

Re:Update?

[Thanshin]

Are these people dim-witted?

One lesson I learned from the game of Go: "If a conclusion depends on the experts being dumb or incompetent, your conclusion is most probably a step the experts already took into account and dismissed as part of their reasoning."

This applies to a lot of fields of science.

Re:Update?

[SJHillman]

Unfortunately, it only rarely seems to apply to politics.

Re:Update?

[Thanshin]

For politics there's the alternative:
"If a conclusion depends on the politician being dumb or incompetent, your conclusion is most probably a step the politician already took into account and dismissed in favor of another one that includes more cash in his pocket."

Re:Update?

[steelfood]

That's exactly it. The question is not, do they even know what they are doing. The question is, what are their motivations. And public service is not a motivation for anybody in the field.

Once you realize that politics is a way for charismatic but otherwise useless individuals to earn a living, then the reasoning behind their actions are clearer. They're functionally no different than used car salesmen, conmen, investment bankers, or MBA's, and serve little other purpose than to leech off society (or in the case of the MBA, the business) while making busy to justify their own existence.

We need an Ark B, and fast.

Re:Update?

[MaskedSlacker]

Swamp gas refracting the light from Venus? Definitely not a supernova though. Those last much longer than a second. One that flashed that brilliantly would have lasted a long while and would have been widely reported. For comparison, SN 1054, which formed the Crab Nebula, was visible to the eye for two years (according to Chinese records).

Response from US military commanders

[Overzeetop]

Really? The whole middle east and north Africa turned into a sheet of glass instantaneously?
Tell me more about this "comet strike" you are proposing...

Re:Occam's razor

[unimind]

Yeah, I don't know what they're talkin about with this "comet". They already figured out where that glass came from. There's obviously no other possible explanation: It was made by the extreme heat from the rocket thrusters of some sort of spacecraft... or possibly a nuclear explosion caused by the aliens.. But that's it. Those are the only two possible explanations.

So did it impact or explode?

[gravis777]

In the headline, it impacted, first sentence it exploded, Second it impacted, fourth it exploded.... So did it impact or explode in the atmosphere? Or did the explosion result in chunks impacting?

Re:Desert 28 Million Years Ago?

[stjobe]

Wikipedia is only a few key-presses away, you know:

The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years.[15] This is due to a 41000 year cycle in which the tilt of the earth changes between 22 and 24.5.[16] At present (2000 AD), we are in a dry period, but it is expected that the Sahara will become green again in 15000 years (17000 AD).
During the last glacial period, the Sahara was even bigger than it is today, extending south beyond its current boundaries.[17] The end of the glacial period brought more rain to the Sahara, from about 8000 BC to 6000 BC, perhaps because of low pressure areas over the collapsing ice sheets to the north.[18]

(emphasis mine)

Re:More information

[fisted]

Oh, really. Thank you AC for pointing this out, the ,,[goatse.cx]'' totally made me believe it was a legit link.