[Worldbuilding] If Earth-ly planet is showered by a meteor rain


#1

Some quick questions here.
Imagine if a habitable earth-like planet (with human already inhabit it) showered by a meteor rain. I’d prefer a rain of smaller meteorites, tho, but feel free to pitch in the idea of a super-meteor slamming earth.

So, yeah.


If such planet is showered by a meteor rain…

  1. How impactful is… the impact?
  2. How’s the ecosystem several years (or decades) after it? The craters? Temporal climate change?
  3. Can the shockwave impact of a meteor induce… say, a volcanic eruption? Like a balloon popped by a needle? Or induce a thunderstorm?
  4. Where are those meteorites go? Can its remnants float around the orbit (and form additional moon)? Or will these floating debris fall back into the atmosphere as another “meteor rain”?

P.S. Nope. I’m not making a game about post or pre-apocalypse, unfortunately. :frowning_face:
But perhaps there’s someone out there willing to weave the thread out of this. :grin:


#2

I’m interested in physics and space, but am by no means an expert. Basically, the only thing I can tell you definitely based on what you have given so far is that all of the above is possible. You can make a meteor rain or a giant impact part of your story. The Earth is actually struck by meteors all the time, and as you can tell it’s not a huge deal.

The only thing I can say for sure is that it’s not something that is sustainable. You can’t have a meteor rain that lasts a hundred years or something. At least you’d have to explain that one. Maybe the planet changed its orbit and its transiting through an asteroid field? Anyway gravity would pull all that material into the planet eventually probably with apocalyptic consequences.


#3

I’m no expert in astronomy too, but I’ll try answering this (CMIIW)

  1. The impact depends on the diameter of meteor and the thickness of the atmosphere of said planet. The bigger the meteor, the bigger the resulting crater, and said meteor has bigger chance surviving friction with the atmosphere.

  2. The impact could result in high amount of dust thrown into the atmosphere, so climate change is very possible (like ice age)

  3. The most immediate result is maybe an earthquake. If you want to implement volcanic eruption, well, you could make the meteor strike a vulnerable plate near a volcano that induce magma eruption or maybe make the meteor strike deep enough to the planet’s crust that it make a new volcano???

  4. If the planet has enough gravity to trap the meteor they could form additional moon(s). Smaller meteor would burn out in the atmosphere, and meteors that just grazed the planet will continue on their orbit.


#4

I recently studied an astrobiology course, so hopefully I can answer :slight_smile:

The strength of the impact depends on the size, velocity, and angle of the objects. Tiny meteors constantly bombard the Earth, but they are rarely noticed, because they burn in the atmosphere. Some years ago a 20m asteroid hit the atmosphere in Russia, and the resulting shockwave shattered windows which injured 1500 people. If you want to really wreck the planet, you have to use bigger asteroids or comets. Comets can be deadlier, because they’re faster.

Through history, asteroid impacts have caused mass extinctions that have killed up to 90% of all species. The species that survive and repopulate the Earth tend to be small, adaptable, not picky about food, quick to mature and breed quickly. New species evolve when competition gets killed off.

Craters can remain for hundreds of millions of years, until erosion and tectonic activity wear them out.

The dust that is flung into the atmosphere by the impact contains CO2 that causes a greenhouse effect, heating up the planet, but because it also covers the sun, the planet eventually cools down again, and an ice age might happen. Edit: The ice age happens first (impact winter), then comes the greenhouse effect.

Shockwaves can cause volcanic eruptions, earthquakes, tsunamis, all kinds of disasters. Not sure about thunderstorms.

Meteorites add to the mass of the Earth. The Moon was formed when a Mars-sized object collided with the early Earth, so an impact that results in the formation of a moon would have to be massive. Some matter is thrown back into space, so maybe it could form rings around the Earth? An apocalypse-scale impact makes the rocks evaporate and literally rain down.


#5

That’s not exactly correct as it’s disputed how moon came to existence but this theory is the most popular one but has failed to explain many things so the currently most " approved " one is that ( in a nutshell ) there was a meteor shower on new earth which made many particles ( rocks ? Can’t remember the exact size so particles for now ) to escape and they started getting accumulated in the orbit which leaded to the formation of current moon.

So yes it can lead to formation of a new moon but that one could collide with the existing one merge with it then the new formed thing could collide With us


#6

I’d suggest checking out the Impact Effects website :smiley:
The main page will estimate various effects based on different impact parameters, and if you click “tell me more” at the bottom, you get a pdf that gives more info on the science involved, and describes more of what the effects would be like.

It depends a lot on how big an object you’re hitting earth with.

On the small scale, a bolide will explode in the atmosphere, so the main effect is the air blast. And that’ll be local. Still, if it explodes above a city… not good for the city. (This is probably what happened in Tunguska in 1908… fortunately, not a particularly populated spot.)

At a dinosaur-killer level, you’re looking at a fireball, which, if it reaches into forest, could spread across all touching forests. You get earthquakes too, though reducing in intensity when you get farther away. Ejecta is debris kicked up by the impact… you can get this landing pretty far away, and fairly close to the impact, that could be a rather thick layer, plus the biggest falling chunks would be like stony hail. Not fun to stand under. And there’s still an air blast… massive gales closer to the impact, triggering storms. Oh, and if it landed in the water, that’s triggering a tsunami. So you’re pretty much devastating a good portion of a continent, putting all that together. But the biggest cause of death would probably be a more long-term subtle effect… all this debris kicked up into the atmosphere is going to block out the sun for years upon years. And you’re going to have acid rain while the atmosphere slowly cleans itself. So, without sun, not only does stuff get cold, but plants die, and algae dies, which means not a lot to eat, and also oxygen levels are going down. The animals that survive the best tend to be small ones, ones that eat detritus and dead things… generalists, mostly.

If you’re talking about something ridiculously big… something bigger than has hit the earth since life got started… then, yeah, you can just melt the whole surface of the planet and vaporize the oceans. This would’ve happened a lot, soon after the Earth was formed, but fortunately it hasn’t happened since then :sweat_smile:


#7

Ouhh… this kind of discussion and underground-conspiracy makes me shiver :hugs:


@cascat07: Of course! Something just can’t stay that way indefinitely!
I’m actually more thinking of a rain that doesn’t lasts that long so the shower only occurred on a one-side of the planet, with the opposite-side knows nearly nothing but to feel the shockwave of the impact :thinking:

So, yeah. There’s some “it’s magic, duh” tricks at play :sweat_smile:


And then shockwave-induced disaster.
(Probably some ppl will consider this topic… somewhat cringy, but I enjoy being lost in such thoughts. These things keep me awake at night :laughing:)

But I’m just not convinced enough if a meteor strike can cause volcanic eruptions. I mean, it’s pretty hard to simulate it even on my mind. Unless the earth plate is somewhat elastic (like balloon), I think the shockwave of impact will be more like “throwing a rock into a lake” rather "popping balloon with needle."


But say, @Lavender. If these meteors contain certain charged metals (think of giant capacitor falling down from sky), can it… interfere the atmosphere and “sparks” certain lightning, at least?

@TSSL that’s a quite thoughtful writing you put there, appreciate it!
And to be frank, I haven’t thought about the Ice Age caused by a meteor rain. Maybe, I don’t want a dinosaur-killer meteor rain happening on my WIP :thinking:
Or am I?


I actually wanted a meteor shower that’s quite devastating, perhaps on par with the dinosaur-killer, but not so powerful that certain genetically-engineered/lucky/powerful human can survive it without underground bunker (natural cave still counts, tho). And the affected area is at most only half of said planet’s surface.

Perhaps, fragments of a passing by giant asteroid can do the trick? Of course this asteroid doesn’t hit the planet, ofc.


#8

Well a earth like planet that was close to a astroid belt but just far enough away that its own gravity well would not have a effect on the belt may allow for a higher frequency of stellar objects to strike whenever other things pass through the belt and change paths of rocks (asteroid belts have many many miles between each unlike the movies on average) this could potentially increase the frequency of seasonal showers as at certain points it would be closer than others, unfortunately this same increase in showers increases the odds of more dangerous ones like earth Enders and increases the odds of near misses but does increase chances that it has many moons.

Edit: I have no actual background in this, just do a lot of research for improved world building for pen and paper rpgs