View Full Version : Someone good with...space! Or asteroids?

06-08-2016, 09:30 PM
I'm writing a story about a person who is spurred to find someone they love due to an unexpected extinction event. I think I've picked an asteroid crashing into us (get out of here, Bruce Willis), but my concern is: wouldn't we see a giant asteroid coming months away? Is it at all plausible that we wouldn't know about a large-enough-to-destroy-the-earth asteroid/comet until like...3 days before it shows up? (I need the event to be far enough away that there isn't much time to plan, but not so sudden that it's like "oh crap, it's he-*DEAD*).

The story is set today, in our world. The idea doesn't need to be flawless, just not distractingly bad. Very little time will be spent discussing the asteroid itself, as the story focuses on the character, not the event.

06-08-2016, 09:36 PM
Yeah, that's possible. Remember the Chelyabinsk meteor? I think you could do some research into your timeline and what you mean by destruction though. There's extinction-level asteroid, and then there's 'destroy-the-Earth' which I'm not sure what you mean there. Also, modern times being what they are, an asteroid like the one that took out the dinosaurs may not do the same for humanity, as dinos didn't have seed banks and bunkers and etc. There's a lot of leeway a lot of places.

In general, we're only looking at a small portion of the sky, and it is possible we wouldn't notice something headed at us until soon before it hit. Soon, also relative. I think both the asteroid movies (the hideous Willis one and the less-hideous Tea Leoni one) had a timeline a couple years out or so to start.

06-08-2016, 10:12 PM

Assuming that 85 percent of the NEOs with diameters larger than 1 kilometer have been discovered, which is close to the present state of affairs, Harris (2009) calculated the hazard statistics shown in Figure 2.7.

That leaves a lot of NEO asteroids unaccounted for and these are just the ones larger than a kilometer. So, yes, one of these could come creeping up on us without anyone noticing, particularly if it had a low albedo. It is quite likely that it would be spotted by amateur astronomers or observatories as it gets closer, but how much time is up to you. 3 days sounds doable. I think you could get away with no warning at all if you wanted.

06-08-2016, 10:17 PM

That leaves a lot of NEO asteroids unaccounted for and these are just the ones larger than a kilometer. So, yes, one of these could come creeping up on us without anyone noticing, particularly if it had a low albedo. It is quite likely that it would be spotted by amateur astronomers or observatories as it gets closer, but how much time is up to you. 3 days sounds doable. I think you could get away with no warning at all if you wanted.

Particularly if it came at us from the direction of the sun

Dennis E. Taylor
06-08-2016, 11:01 PM
Particularly if it came at us from the direction of the sun

Beat me to it. Have it come around the sun, approaching us from dayside. If it's a first timer, i.e. never been seen before, there's no reason for anyone to know about it until it comes around the sun. Amateurs generally won't be looking in that direction, and anyway it's a lot harder to see as long as it doesn't quite come between us and the sun (Otherwise solar astronomers would be saying, "Hey, what's that spot?").

02-08-2017, 06:50 PM
You could also limit it to a regional extinction event, which could make the asteroid smaller and far more likely to creep up on us undetected.

King Neptune
02-08-2017, 07:15 PM
Even if it is seen approaching, a large asteroid couldn't be evaded or destroyed, so people could just watch inevitable doom approaching. If its approach was known years in advance, then something could be done, but if its approach was only known six months before impact, then a few ICBMs could be thrown at it, but that probably wouldn't be effective.

02-08-2017, 09:47 PM
Not as big as an Earth destroyer, but a 1,300-foot asteroid snuck up on us in 2015.

HOW DID THE HALLOWEEN ASTEROID SNEAK UP ON US? (http://www.popsci.com/how-did-halloween-asteroid-sneak-up-on-us)
Asteroid 2015 TB145 was difficult to spot because it has a strange orbit, he says.
The Sun and the planets are arranged in a flat disk shape. This is called the ecliptic plane. Most of the asteroids in the belt between Mars and Jupiter can be found along the ecliptic plane, too, but the "Halloween asteroid" is different. If you could look at the solar system from the side, 2015 TB145 cuts a path at a 40-degree angle to the line of the ecliptic plane.
"So it's in a region of sky where there aren't many asteroids, a region of sky that's not searched as often," says Chodas. "It's a tribute to the thoroughness of NASA's surveys that, even though it was difficult to detect, we caught it."

There are some other possible extinction events. The acidity of the ocean from excess CO2, for example, might cause a collapse of the food supply. A gamma ray burst too close to the Earth will be an extinction event we don't see coming. The Sun is capable of sending a proton storm toward us that could be devastating and we'd only have about 24-28 hours warning.

Ocean Acidification (http://ocean.nationalgeographic.com/ocean/explore/pristine-seas/critical-issues-ocean-acidification/)
Since the beginning of the industrial revolution in the early 1800s, fossil fuel-powered machines have driven an unprecedented burst of human industry and advancement. The unfortunate consequence, however, has been the emission of billions of tons of carbon dioxide (CO2) and other greenhouse gases into Earth's atmosphere.

Did Deadly Gamma-Ray Burst Cause a Mass Extinction on Earth? (http://www.livescience.com/49040-gamma-ray-burst-mass-extinction.html)

Did A Massive Solar Proton Event Fry The Earth (http://www.spacedaily.com/reports/Did_A_Massive_Solar_Proton_Event_Fry_The_Earth_999 .html)
Close to the end of the last ice age there was a sudden disappearance of many mammalian species which some paleontologists say was the most severe since the disappearance of the dinosaurs 65 million years ago. In North America 95 percent of the megafauna became extinct, these being predominantly mammals having body weights greater than 25 to 50 kilograms. But even small animals were affected, as in the disappearance of 10 genera of birds.

Although North America was most affected, it had a severe impact also in Europe, Siberia, and South America. The cause of the extinction has long remained a mystery. Theories that have been put forth have ranged from overkill by North American paleolithic hunters to the impact of a large comet or swarm of meteors. But all have been shown to have serious flaws.

Now, Starburst Foundation researcher Dr. Paul LaViolette has found evidence that this mysterious die-off may have had a solar flare cause.

A super volcano eruption is another possibility.

02-11-2017, 09:12 AM
The physical collision of the Earth and asteroid alone isn't what causes the extinction event (except for near the impact site). The impacts usually trigger massive tsunamis. Also, debris gets thrown into the atmosphere which can push the Earth into a nuclear winter i.e. particles in the atmosphere reduce incoming solar radiation reducing global temperatures for a few years which was a contributing factor to the decline of dinosaurs. Anyway, my point is you could have a situation where a smaller meteorite crashes into Earth (i.e. not big enough that it's the centre of the story but it still might make the evening news so it is in the background of your story) and lands in the Pacific ocean triggering a giant tsunami. It can take 12-24 hrs (might want to double check that) for a tsunami wave to cross the Pacific to give you the delayed catastrophe.

02-11-2017, 02:28 PM
An asteroid large enough to create an extinction event will not make humans extinct in a day. It will be a prolonged death, with probably 95% of humans dead within the first 6-10 months. Crops won't grow because of the aforementioned nuclear winter, so humans will have to persist on existing stocks of food. Some will still have refrigeration, and fuel for powering refrigeration for a few months. Only nuclear and hydro power could persist. Petroleum products will deteriorate and be useless within 18 months. The long-term problem will be that the more people surviving the more people to feed and the faster the food stocks are consumed. Special quarters could allow some to endure the calamity and come out the other side, assuming they are not raided by others less secure.

02-11-2017, 04:19 PM
A lesser version of that nuclear winter (think Westeros winter) led to three years of worldwide climate disruption, crop failures and famine after the eruption of Mt. Tambora in 1816. http://www.branchcollective.org/?ps_articles=gillen-darcy-wood-1816-the-year-without-a-summer

This is well documented and would likely have very similar effects on the developing world, while causing social unrest everywhere. There's also the eerie coincidence of a hundred year cycle of having a catestrophic war immediately followed by a huge natural calamity, with the other being the 1918 flu pandemic, and hey we're at that time of the century again with world leaders going "hold my beer and watch this....!"

02-12-2017, 07:01 AM
Three days . . . maybe not. But the time frame to do something about an approaching big impactor would have to be much longer than that. Back in the late 19th Century, astronomer/novelist Camille Flammarion wrote a fine and prescient science-based novel titled Omega about a cometary impact that was foreseen and inevitable many months in advance. We could detect a big impactor on the right trajectory several years in advance, and be unable to do anything about it except maybe close our eyes and plug our ears.


L.E.N. Andov
03-07-2017, 07:01 AM
Asteroids often have significant quantities of metals. Some metals are toxic to ?% of the species on earth. There is also the possibility of what the asteroid hits. Do you want the reunited couple to have forever after in a primitive setting? Or do you want them to have three days together before tshtfan? Because of the possibility of exotic metals or even undiscovered atoms/molecules you have an opportunity for the asteroid to disrupt utilities. Do survivors have to climb to higher ground? Or is life as we know it only possible at the coast for some reason. Does your impactor need to kill everything or just end "life as we know it?"