"Fiery crashes" (simulations)

Palomar7 · 2018-01-09 10:09:04

How The Universe Works often has depictions of planets colliding with fiery impacts.

Now I'm seeing simulations of asteroids colliding, with flashes of fire.

Would colliding asteroids produce a flash of fire? If yes, why? Friction?

RobertDyck · 2018-01-09 11:00:37

My understand is "it depends". If a rock bounces off, then no. If it hits with enough force to "squish" solid rock, then the friction of rock sliding against rock, or energy needed to squish solid rock like a piece of Plasticine would generate a lot of heat. That heat could melt rock. If it heats enough to melt rock like lava, then it would be red as lava. That wouldn't exactly be fire, but would be a splash of red hot molten rock. Small rocks would bounce or break, but asteroids could squish causing what is effectively lava. Probably wouldn't look exactly as depicted.

However, when an asteroid hits Earth, our planet has a relatively thin crust. Current scientific belief is that our planet was heated by these same forces. Large asteroids collide causing the rock to squish, which causes them to melt. Once they're soft, the next rock that hits will stick rather than bounce off. Energy of that hit will add more heat. Earth is 12,750km diameter, the crust under the ocean is "5 km (3 mi) to 10 km (6 mi) thick and composed primarily of denser, more mafic rocks", while contents are "30 km (20 mi) to 50 km (30 mi) thick and mostly composed of less dense, more felsic rocks". I'm not familiar with the geology terms, but continents are lighter rock so they float higher. All crust floats on red hot stuff of the mantle. When a volcano erupts, that shows you what's down there. Actually, geologists tell me most of the mantle is more like Pasticine due to pressure of miles of rock sitting on it. It only becomes liquid when pressure is released, such as a crack in the crust, or a hot spot melts it. But imagine what happens when an asteroid hits.

TV likes to show a video simulation of the asteroid that killed the dinosaurs. That was the most recent big asteroid, somewhere between 66 and 68 million years ago. It was 6.2 to 9.3 miles (10 to 15 km) diameter. It hit the Gulf of Mexico off the Yucatan peninsula. And it wasn't a normal asteroid; most asteroids are rock. This one was solid metal like a meteorite. Astronomers tell me only 4% of near Earth objects are metal. We know what it was made of because a layer of debris covers the Earth. The asteroid pulverized, splashed up from the impact. But imagine this: water of the Gulf of Mexico as deep as it is today, the ocean floor just 5 to 10 km thick, the asteroid diameter as big as the thickness of the crust, under that is thousands of kilometres deep molten magma of the mantle. That would create one hell of a splash of red hot stuff. Magma is lava with volatiles dissolved in it: steam, sulphur dioxide, carbon dioxide, etc. Think of magma like a bottle of soda pop, and lava is like soda that went flat. But when the asteroid hit, not only did it splash off the crust revealing the mantle underneath, but the mantle is composed of pressurized magma. All that steam etc pressurized by miles of rock sitting on it. All that pressure would have been released when the crust was smashed off. Geologists say there are streaks of debris all along North America. They found the crater by following the streaks back to where they converged. But there are streaks of stuff from Yucatan to Alaska. That was one hell of a hit!

Last edited by RobertDyck (2018-03-30 14:57:14)

Palomar7 · 2018-01-09 19:04:44

Thank you, Robert. I read entirety.

I had "Hollywood" in mind when seeing the "fiery asteroid crash" (more like a hard bumping into each other) on that show but thought I'd ask (US is so saturated with/by Hollywood...gets exasperating).

[asteroid that killed the dinosaurs] Geologists say there are streaks of debris all along North America.

I haven't actually checked (Google) but the many "kettle lakes" in Minnesota come to mind. Will do that now.

p.s.: Nothing about Minnesota in this http://time.com/4371446/these-tranquil- … t-craters/

Will keep searching (btw - Quebec seems a favored asteroid target). :-]

Last edited by Palomar7 (2018-01-09 19:12:27)

vemsemigma · 2018-03-30 14:20:36

You should probably get a reading about this. The mojo bag you want is fiery wall of protection.

Mars_B4_Moon · 2022-04-25 14:35:26

Western University’s all-sky camera network captures large fireball near Lake Simcoe
https://london.ctvnews.ca/western-unive … -1.5866067

All-sky cameras capture bright fireball event
https://phys.org/news/2022-04-all-sky-c … eball.html

Mars_B4_Moon · 2022-07-27 05:40:12

Mapping the Sky: Finding asteroids requires a combination of tools
https://spacenews.com/mapping-the-sky-f … -of-tools/

“A single strike could reshape our world, and the only thing that can stop it is science.”
Those are the opening lines of “Asteroid Hunters,” an IMAX film narrated by Daisy Ridley of Star Wars fame. If a June 17 screening near the NASA Ames Research Center is any guide, “Asteroid Hunters” achieves its goal of underscoring the threat asteroids pose and the opportunity to deflect a dangerous one headed toward Earth.

tahanson43206 · 2022-07-27 06:40:00

For Mars_B4_Moon ... thanks for bringing this topic from 2018 back into view....

RobertDyck provided an interesting and detailed reply to Palomar's question about animation of celestial events.

And! Thanks for the head's up !!! about the IMAX film ... it ** should ** now circulate to an IMAX theater "new you" .... I'll watch for it.

(th)

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#1 2018-01-09 10:09:04

"Fiery crashes" (simulations)

#2 2018-01-09 11:00:37

Re: "Fiery crashes" (simulations)

#3 2018-01-09 19:04:44

Re: "Fiery crashes" (simulations)

#4 2018-03-30 14:20:36

Re: "Fiery crashes" (simulations)

#5 2022-04-25 14:35:26

Re: "Fiery crashes" (simulations)

#6 2022-07-27 05:40:12

Re: "Fiery crashes" (simulations)

#7 2022-07-27 06:40:00

Re: "Fiery crashes" (simulations)

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