# Can the pitch and speed of an asteroid cause a less catastrophic results? [duplicate]

Notice that most of the energy is absorbed by the inside with considerable little damage to the outside. I base this question on the premise of would the Earth and asteroid would act similar.

I asked this question at physics.SE: https://physics.stackexchange.com/questions/269610/could-a-meteor-cause-the-flood-from-noahs-time-in-the-bible in the very beginning of learning SE formats of what a good question is. I have refined on it and hope it does better here.

Using the Bible as a historical record. It says that before Noah's flood people lived to be around a thousand years old about 1000B.C. Therefore, either people really lived to be that old or perhaps the Earth spun much faster at that time. Shortly after the flood human life span dropped to 120 years to more-or-less what we experience today. It also said that was the first time it rained when the flood started and the first rainbow was witnessed when it stopped. I'm sure there was other survivors around the world but for this region of Earth this is what people experienced.

Therefore, could it be possible that:

• An asteroid hit at an angle to slow the Earth's rotation and to increase its axial tilt to give birth to seasons? With the Earth suspended in space some or more of the asteroids inertia would transfer to Earth rotational or orbital inertia.

• An asteroid passed through the crust like a bullet causing little damage externally but changing the magma flow to decelerate the Earth's rotation? It would still leave a creator but the bulk of the impact would be absorbed by the inside of the Earth.

• An asteroid struck such that the polar caps melted or the water was forced out of the oceans?

The Earth can physically have 1.7 hour days before spinning apart. I understand speed, composition, angle crust depth and many other factors would change the outcome of an impact. I am looking for a scenario where where it not end of all life, but significantly changed the Earth.

By some possibility this could be how an asteroid could react to the Earth's surface depending on angle.

## marked as duplicate by StephenG, John Dallman, L.Dutch♦, ZioByte, AshJan 28 '18 at 10:22

• @Muze Even though your question on Physics.SE was closed, you accepted an answer that addressed all the points you've raised here. What do you want to gain from this question which you didn't get on Physics.SE? – Rob Jan 21 '18 at 23:46
• Are you aware of the fact that even if the Earth spun faster around itself, a year would still be defined as one revolution around the Sun? So if the Earth spun faster, we'd just have 500 or 1000 days in a year, but purple still wouldn't live for more years than they usually do. – ZeroOne Jan 22 '18 at 6:37
• Trying to use Worldbuilding to "investigate" whether a biblical flood is plausible or not seems off topic, and the fact that he OP posted a similar question on Physics SE means it's also effectively cross posted. – StephenG Jan 22 '18 at 7:01
• There are so many basic flaws in the assumptions behind the question that I don't think a Q&A format will be helpful to you unless you really break it down and ask very specific questions. For example is it possible to make the year shorter, could an asteroid change year length, etc are all big questions in their own right. You could try joining the chat chat.stackexchange.com/rooms/17213/the-factory-floor – Tim B Jan 22 '18 at 16:10
• The really neat slo-mo of the bullet going through the ballistics gel seems to end just before the collapse of the cavitation produces enormous pressures and heat, potentially leading to a mini-nuclear-explosion.flash. – Justin Thyme Jan 28 '18 at 4:21

Your fundamental (pun intended :-)) problem lies in using the Bible as a historical record. The simple answer is that none of those things could happen without, at the very least, leaving ample evidence that they had happened. More probably the result would have been the extinction of all life.

The reasons why Noah's Flood simply could not have happened (absent miracles) as described in the Bible are amply covered elsewhere. Of course to some primitive tribe, "the whole Earth" might be an area of a hundred miles (km, leagues, &c) or so in diameter, so tribal myths of something like the Black Sea filling could have gotten exaggerated.

But to take your three suggestions:

1) An asteroid strike sufficient to change the Earth's rotation & axial tilt would have reduced the entire Earth to a molten blob. In fact something of the sort probably did happen in the very distant past (about 4.5 billion years ago), resulting in the creation of the Moon. See e.g. https://en.wikipedia.org/wiki/Giant-impact_hypothesis

2) An asteroid would not pass through the Earth's crust. Any asteroid large enough to keep going after contact would be of the Giant Impact scale, so there wouldn't be anyone left. Smaller ones would simply hit and vaporize, causing major damage. See the evidence from a number of actual impact craters, notably Chicxulub (responsible for the extinction of the dinosaurs), or smaller craters like Sudbury & Arizona's Meteor Crater.

3) Even if an asteroid impact could melt the polar icecaps, a) there's only enough water to raise sea levels about 100 meters, not enough to cover the whole Earth; b) the melting would have left unmistakable traces, as did the melting after the last Ice Age; c) the ice caps most likely wouldn't have regrown yet, and finally; d) core samples show that they've been in place for at least 100K years: https://en.wikipedia.org/wiki/Ice_core

An asteroid which hit the ocean might have caused floods, but they'd be tidal waves, not 40 days & nights of rain.

Finally, even if these had happened, changing the rotation speed of the Earth changes the length of the day, not the year. To lengthen the year, you'd have to move the Earth farther from the Sun. If it were close enough to the sun for its year to be 1/10 of the present length, it would be uninhabitably hot. Even Mercury's year is only about 1/4 of an Earth year.

• It may also change in orbit – Muze Jan 21 '18 at 21:59
• distance from the sun is a function of the orbital distance and speed, you can't change one without changing the others. – John Jan 22 '18 at 0:07
• @Muze: To have a shorter year, you have to orbit closer to the sun. This means your planet gets MUCH hotter. Mercury (which isn't anywhere near as close as you'd need to be for a year of the length you want) hits 800F (427C). – jamesqf Jan 22 '18 at 4:33
• it was closer to the sun then – Muze Jan 22 '18 at 4:52
• @Muze: No, if it was close enough to the sun to have a year as short as you want, the surface would have been pretty close to red hot. Certainly all the water would have been turned to steam, making it pretty difficult to have a flood :-) Then you have the problem of how it got moved from that orbit to its present one. It just isn't going to work: the Bible is neither historically or scientifically accurate, it's a collection of the tribal myths of a bunch of wandering shepherds. – jamesqf Jan 22 '18 at 19:31

Therefore, could it be possible that:

• An asteroid hit at an angle to slow the Earth's rotation and to increase its axial tilt to give birth to seasons?

An impact powerful enough to do this would leave the Earth a ball of magma. All life would be destroyed.

• An asteroid passed through the crust of the Earth, causing little damage externally but changing the magma flow to decelerate the Earth's rotation?

Can't happen. It would be stopped (like the hypothetical early planet-sized body Theia, which -- according to the giant impact hypothesis -- slammed into Gaia, merged with it, and spit out The Moon while renaming Gaia into Earth), it wouldn't pass through.

• An asteroid struck such that the polar caps melted or the water was forced out of the oceans?

An impact event certainly could melt polar caps. That wouldn't explain where the water went afterwards, though, and the caps simply don't have anything like the water needed anyway.

• @Muze: The answer explains that an asteroid hitting the Earth with sufficient momentum to have a material effect on its rotation will necessarily carry enough energy to melt all the crust. Instant end of life. – AlexP Jan 21 '18 at 20:51
• @Muze: Can't happen. Anything that falls from outer space hits with at least escape velocity, which is ~25,000 mph/11.2 km/sec. If it's small, like a meteorite, it can be slowed by air friction, but that heats it to incandescence, which is why we see meteors. – jamesqf Jan 21 '18 at 21:00
• @Muze, it's real simple: Any object with enough momentum to significantly change the rotation of the Earth will --among other minor side-effects-- easily destroy all life many times over. Absolutely no chance of survival by even the deepest fishes in the sea. Not even bacteria will survive. Whether it's fast or slow or the angle of strike or the thickness of crust -- those matter for how much the rotation changes, but all life is utterly dead regardless of how you fine-tune it. Mass-extinctions were caused by teeny asteroids (5-10km) that had insignificant effect on rotation. – user535733 Jan 21 '18 at 22:53
• @Muze The core was molten before Theia. What it melted was the surface. And you completely misunderstand Theia--it wasn't volcanic, it was a Mars-size world that did a glancing blow. – Loren Pechtel Jan 22 '18 at 1:05
• @Muze: But physics does't care whether you believe or not :-) Which is the main difference between physics and religion. – jamesqf Jan 22 '18 at 4:27

I'll try to contribute, trying to omit what others have already mentioned;

The first issue I want to mention is your idea that an asteroid would 'go through' Earth just as the bullet does through the high-tech jelly. This analogy is deeply flawed due to one simple thing that you have ignored:
There is actually a lot of physics involved in stopping something when hitting something else, but it can all be broken down to a rule-thumb:
For high-velocity impacts, if the density contrast between impactor and impactee is high, one will ignore the other. If not, both break apart. (Over at astronomy we think a lot about impacts)

What do I mean by this? See the bullet is much denser than the medium it is shot into. But 'much' I'm talking about around a factor of 5-10 density contrast. After the initial expansion shock visible in the animation, the gel medium more or less ignores the bullet.
The same thing would happen If you shoot a bullet into water (well, because it has nearly the same density as the gel),or air (duh, but the principle still applies).

Now if you shoot it at something even denser, like a brick, or a metal plate, the bullet will not penetrate anymore.

Now imagine the bullet is a meteor and doesn't have the same material strength as the bullet, then it will simply fly apart. Large rocks ($\ge 100 km$) in space have comparable densities, so they will always be ripped apart, never penetrate.
Smaller rocks will always be ripped apart, without affecting Earth significantly, because they have similar density, but the small rock also has much less momentum.

I mentioned this to maybe guide your thinking in physical terms: Density contrast and momentum (but that was already mentioned in other answers). I find most of your questions that you had in the comments in your physics.se answerable just by looking at this principle.
If you want to, this can be a valuable tool in world-building, as well as in bible studies, depending what your aim is.

So what you want to do is essentially send a mini-black hole through earths crust and still keep the solar system and the planetary atmosphere in a good shape after that. That would be a tough one.

1.) An asteroid hit at an angle to slow the Earth's rotation and to increase its axial tilt to give birth to seasons?

2.) An asteroid passed through the crust like a bullet causing little damage externally but changing the magma flow to decelerate the Earth's rotation? It would still leave a creator but the bulk of the impact would be absorbed by the inside of the Earth.

3.) An asteroid struck such that the polar caps melted or the water was forced out of the oceans?


1.) As others said, that's not possible. But I think the other answers underappreciated how NOT POSSIBLE this is.
To go from a 1.7 hrs rotation period with the whole mass of Earth to 24 hrs in one impact would deposit a lot of kinetic energy in the crust. So much in fact that the energy deposited would easily reach the gravitational binding energy of the planet.
Meaning: This would be an impact that could rip the planet apart. It wouldn't just be catastrophic, apocalyptic or hyper-bad. It would be fatal. I can show you the math if you're interested, it's simple.

And as soon as you go down in impact energy, you can't produce the slow-down anymore that your source is citing.

I have discussed 2.) above already.

3.) is an entirely possible scenario, and probably happened multiple times during Earth's early history, during the Late heavy bombardment period.

However it is important, that this happens before the development of complex life, or else everything has to start from zero again. To give you a sense of comparison, the K-Pg impactor (the Dinosaur Killer, around $\rm 10 km$ in size) wouldn't have near enough energy to affect the polar caps significantly or to evaporate any ocean.

To do this, you need a bigger meteorite (or asteroid with $\rm \ge 100km$ size, as you asked for) and then consequences are again dire:

The splash energy (and as discussed, the density principle needs it to be a splash) would be incredible, melt the whole surface, even eject a good part of the atmosphere mechanically.
But only after that comes my favourite part: Atmospheric escape. The extremely hot surface would heat the atmosphere to temperatures where it can escape in bulk.

Summarizing

No impactor scenario that I can think of fulfills all the possible consequences that you need in your story.

• Of course you can leave out the part with changing the rotation period of the planet, because that places the hardest physical bound on a planet-destroying impact.
• The 'going-through-Earth' thing would also have to be abandoned on a realistic ground. Except you want to invoke really many rogue neutron stars / black holes flying around in the universe and hitting Earth by chance.
• Melting the polar caps / evaporating the oceans should be fine, but then you have to live with the other consequences as well. Or you magic them away.
• Good info! WRT bullet analogy, typical bullets have a muzzle velocity 120-1200 m/sec. Anything hitting Earth from outside is going to have a minimum velocity of 11.2 km/sec, so a minimum of 100X the energy. So a bullet-sized meteor hitting the atmosphere (much thinner at altitude than ballistic gel) heats to incandescence in a second. A larger asteroid - say dinosaur killer size - doesn't fail to penetrate the surface as a bullet would, it vaporizes much of itself and the surface it strikes: bbc.com/earth/story/… – jamesqf Jan 22 '18 at 19:55
• I guess a mini black hole running at the earth at high velocities would just make a narrow hole (and come out at the other side) without much changing the rotation or orbit. No big effect at all. – Paŭlo Ebermann Jan 22 '18 at 20:09

See Carolina bays, the younger Dryas impact event, Carlson... in a nutshell, about 13,000 years ago, at the end of the last ice age, when there was a 2 mile tall glacier covering the north pole from Moscow, France, England, New York to northern China... a comet, approximately 6+ miles in diameter, impacted where the great lakes are now (after having broken into several to a dozen or more pieces) and a few other areas in what is now Canada at over 40k miles per hour. The great lakes and possibly the grand canyon are leftovers from this event? This is new science information... totally legitimate. The grand canyon part is mine... within 30 minutes of the impacts, all of North America from Virginia to California to Northern Mexico was on fire. Approximately 3 million ejecta re-entered the atmosphere with speeds from 6k to 10k mph, ranging in size from 100 feet to a mile or more... chunks of ice from the glacier. Just look at the 500k plus impact craters discovered with lidar from orbit in the last 15 years, covering the east coast from Virginia to Florida to Kansas... all of them oval shaped with their long axis pointing to the great lakes! search youtube..

• Welcome to Worldbuilding, CharlesBrown, this is an interesting piece of geological history. Your answer can be improved with a citation of a source for this information. Thanks if you can do so. Have fun here! – a4android Jan 22 '18 at 3:41
• Why would I believe anything on YouTube (assuming I watched online videos)? How about citations from reputable peer-reviewed journals? There is a published hypothesis regarding a Younger Dryas impact (overview: en.wikipedia.org/wiki/Younger_Dryas_impact_hypothesis ), but it's much less drastic than you make out. It wouldn't have created the Great Lakes (and what of the other great lakes in Canada - Winnipeg, Great Slave, and Great Bear?), much less the Grand Canyon. – jamesqf Jan 22 '18 at 4:39
• This didn't happen. – kingledion Jan 22 '18 at 14:26
• The grand canyon formed through erosion as the land rose - water vs rock not rock vs rock. – Tim B Jan 22 '18 at 16:11
• @Muze: If you post a question on the Earth Science site, someone might be kind enough to point you to the very large amout of evidence that shows that the Grand Canyon was eroded gradually, over millions of years. There are examples of fast erosion: e.g en.wikipedia.org/wiki/Bonneville_flood and en.wikipedia.org/wiki/Missoula_Floods They leave behind unmistakable evidence. – jamesqf Jan 22 '18 at 19:26