Grand Canyon-Sized Valleys On the Moon Formed Within 10 Minutes (space.com) 25
A new study reveals that two Grand Canyon-sized valleys were formed in less than 10 minutes by "floods of rocks traveling as fast as bullets," reports Space.com. From the report: Scientists analyzed the lunar canyons, named Vallis Schrodinger and Vallis Planck, to find that these huge valleys measure 167 miles long (270 kilometers) and nearly 1.7 miles (2.7 km) deep, and 174 miles long (280 km) and nearly 2.2 miles deep (3.5 km), respectively. In comparison, the Grand Canyon is 277 miles long (446 km) and is, at most, about 1.2 miles deep (1.9 km), the researchers noted. [...] This pair of lunar canyons represents two of many valleys radiating out from Schrodinger basin, a crater about 200 miles wide (320 km) that was blasted out of the lunar crust by a cosmic impact about 3.81 billion years ago. This structure is located in the outer margin of the moon's largest and oldest remaining impact crater, the South Pole-Aitken basin, which measures about 1,490 miles wide (2,400 km) and dates about 4.2 billion to 4.3 billion years old.
[...] The scientists estimate that rocky debris flew out from the impact at speeds between 2,125 to 2,860 miles per hour (3,420 to 4,600 km/h). In comparison, a bullet from a 9mm Luger handgun might fly at speeds of about 1,360 mph (2,200 km/h). The researchers suggest the energy needed to create both of these canyons would have been more than 130 times the energy in the current global inventory of nuclear weapons. "The lunar canyons we describe are produced by streams of rock, whereas the Grand Canyon was produced by a river of water," [said David Kring, a geologist at the Lunar and Planetary Institute of the Universities Space Research Association]. "The streams of rock were far more energetic than the river of water, which is why the lunar canyons were produced in minutes and the Grand Canyon produced over millions of years." The findings have been published in the journal Nature.
[...] The scientists estimate that rocky debris flew out from the impact at speeds between 2,125 to 2,860 miles per hour (3,420 to 4,600 km/h). In comparison, a bullet from a 9mm Luger handgun might fly at speeds of about 1,360 mph (2,200 km/h). The researchers suggest the energy needed to create both of these canyons would have been more than 130 times the energy in the current global inventory of nuclear weapons. "The lunar canyons we describe are produced by streams of rock, whereas the Grand Canyon was produced by a river of water," [said David Kring, a geologist at the Lunar and Planetary Institute of the Universities Space Research Association]. "The streams of rock were far more energetic than the river of water, which is why the lunar canyons were produced in minutes and the Grand Canyon produced over millions of years." The findings have been published in the journal Nature.
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It's pretty useless if you're from a society where seeing bullets is restricted to people paid to act psychotic (soldiers, police with weapons training) and the actually psychotic ("private" gun owners).
The closest I've come to seeing a bullet is when I've brought rabbit from the butcher and found shotgun pellets in it. Is that the size of a bullet? Bigger? Smaller? "9mm" is the size of the cartridge - but that isn't necessarily the size of the bullet that comes
Why this obsession with denying Nature? (Score:2)
The phenomenon being described had the kinetic energy of 100 times our entire nuclear arsenal.
The hell metric would have been appropriate to use here? Sticks and stones?
Nature is horrifically violent. We are no different. Stop denying that reality already.
Re:Why this obsession with denying Nature? (Score:4, Interesting)
Okay, you've got a point. But.. I got Claude! ;) Claude says:
"The collision that created Schrodinger basin unleashed the power of 4-5 dinosaur-killing asteroids striking simultaneously. While the Chicxulub impact on Earth threw up enough dust and debris to block out the sun and trigger a global winter, the Schrodinger impact was so powerful it would have briefly turned portions of the Moon's surface into a sea of molten rock, spraying debris across thousands of kilometers. Some of this ejected material would have escaped the Moon's gravity entirely, creating a spectacular display visible from Earth."
then.. "What's particularly fascinating is that Schrodinger basin isn't even the Moon's largest crater - it's impressive at 320km across, but the South Pole-Aitken basin is about 2,500km wide!" Okay Claude.. go for it.
The South Pole-Aitken basin impact was truly mind-boggling. Let's try to capture its scale:
"Imagine not just 4-5 dinosaur-killing asteroids, but hundreds of them striking at once. The impact that created the Moon's South Pole-Aitken basin hit with such devastating force that it likely punched through the Moon's crust entirely, exposing the deeper mantle beneath. If such an impact happened on Earth today, it would melt an area larger than the United States. The collision sprayed molten rock and debris so far that some scientists think fragments from this single impact might be found across the entire surface of the Moon - and some pieces may have even reached Earth itself. The crater it left behind is so massive that if you were standing on one edge, you couldn't see the other side even if there was nothing in your way - the Moon's curvature would hide it from view."
FWIW other Schrodinger basin creation energy equivalents (not as violent) from Claude are:
Some potential metaphors could be:
Earth's natural phenomena: "The impact that created Schrodinger basin released energy equivalent to millions of the largest earthquakes ever recorded combined" or "The energy released was greater than all volcanic eruptions in Earth's recorded history multiplied thousands of times over"
Solar energy: "The amount of energy that struck the Moon to create this crater equals all the solar energy that falls on Earth over several days" (This one is particularly interesting as it connects to a cosmic scale while using a familiar reference point)
Global power consumption: "The impact released energy equivalent to humanity's total electricity consumption over several decades"
Anyway to each his own but I find Claude's descriptions to be more useful being comparison to other celestial impacts, than TFA where it is difficult, though not impossible, to understand nuclear arsenal as a unit of measure.
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All I get from this is that Chicxulub carried the energy of 20-25 times our entire nuclear arsenal.
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Who cares what your friend (or cat?) Claude says? You've got the link to the paper. Why not read that. If you're not going to understand the paper, then regurgitating your cat's digestion of the paper isn't going to help you to understand it.
Just read the frigging paper. Nature rarely goes over 3 pages for a paper, so it's not going to take long. Then you've only got to deal with your inability to understand the paper, not add in your cat's misun
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I didn't even understand it well myself until just now checking it out.
You just answered your question.
Why the metaphors for scale? Because people don't understand scale well.
(Still-- they got the metaphors wrong. We need to know how many Olympic swimming pools that rock flow would fill per second!)
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>
(Still-- they got the metaphors wrong. We need to know how many Olympic swimming pools that rock flow would fill per second!)
Or how many bananas.
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10 minutes (Score:2)
I need to know what that is in terms of bicycle wheel turns at 25 mph.
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With summer or winter tires?
Wouldn't the rocks just shatter? (Score:2)
Surely travelling at that speed and hitting the ground they'd simply shatter (or if hot from the impact just squash) or at least be deflected in random directions, they wouldn't all carry on for miles and miles in a dead straight line all in exactly the same direction with a few degrees digging a huge valley as they went. This theory seems a very odd way to explain these features.
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Rock isn't like a metal bullet. It shatters in high speed impacts particularly if its hitting something as hard as itself.
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Also, most bullets aren't particularly hard metal. Density is more important. Someone might make bullets of tungsten carbide (sintered density up to about 16, but variable), but for making armour-piercing bullets the military go for relative
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Surely travelling at that speed and hitting the ground they'd simply shatter (or if hot from the impact just squash) or at least be deflected in random directions, they wouldn't all carry on for miles and miles in a dead straight line all in exactly the same direction with a few degrees digging a huge valley as they went. This theory seems a very odd way to explain these features.
There is no atmosphere to interfere with the behavior of objects hurtling towards that body and impacting it. So we would have to take that into account when trying to calculate the end result. I say calculate, because we may not have the capability to replicate, even at micro scale.
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NASA built a hypervelocity gun that can get into those velocity ranges. I forget which state it's in, but I remember the hubris in the serial number cast into the ironmonger of the barrel mounts - "#01". Someone at the foundry thought there might be a second order for this barrel support.
The purpose of the gun was to examine the effect of hypervelocity projectiles (so, what projectile materials? Many. Which imposed design constraints
Erosion comes in so many forms (Score:4, Informative)
FWIW, the current theory is the Grand Canyon was formed by the uplift of the Colorado Plateau and its subsequent erosion by the river. Yes, the Canyon was "cut" by the Colorado river, but basically the river stayed level while the ground rose around it.
Erosion comes in so many forms, and here on earth water is almost always involved. It's interesting to discover a form not based on water. At the speeds described, I would imagine some of the moon rock would be approaching a melting point during collision.
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dating of cave sediments and flowstone deposits on the plateau around the Canyon allow dating and measurement of both the time of uplift, and the degree of tilting at different times in the process. It was a very neat piece of work - I remember reading the paper when I subscribed to Nature, so that would have been about 1997 or '98.
There are probably creationists who don't like the dating of the ground m
Vallis Schroedinger? (Score:1)
Better check again to make sure it's still there.
Ancients (Score:3)
The force and velocity I believe. How do they know the exact cause? Would we have record of those additional rocks somewhere?
The ancients (Greeks specifically I believe) told of the gods of the sky being in a kinetic war, with bolts of lightning and all such things.
Given we live on an electromagnet in a large solar system sized electromagnetic system, it's plausible to me that there may have been a comet or something else in the solar system (eg. perhaps another planet, such as the one(s) that created the Van Allen Belt) could've passed the moon and discharged significant (static?) electricity. That would have the force necessary to carve such canyons quickly.
On the scale of 6,000, 12,000 years, during prior civilizations, not probably, but perhaps further back. But maybe the Ancients observed something similar.
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The Earth created the Van Allen belt. It did so about 0.78 million years ago - the last time the Earth's magnetic field decreased to zero. (More precisely, to a net zero ; it probably had small areas of field of varying polarity rather than an "absolute" zero.)
You're conflating reality (look around you - kick something - "reality" is what makes your toe hurt.) with an SF superweapon. Specifically L
How many Nelson’s Columns? (Score:2)