Basic Information
Meteors are small interplanetary bodies that hit a planet. Asteroids are larger rocks orbiting our sun, and from time to time such rocks cross our orbit and hit the Earth.1
The vast majority of meteor impacts are completely harmless, but there have been a fair number of meteor and asteroid impacts on Earth in pre-human history that have caused large-scale devastation. In theory, a large enough asteroid hitting Earth could wipe out all higher life forms.
Specific asteroid or meteor impacts/events:
- The Tunguska Event may have been a meteor or asteroid impact.
- The Nemesis (Star) Theory is that extinctions have happened in cycles caused by a dark star that hurls meteors or comets through our solar system.
- The Peekskill Meteorite of 1992 was so bright and noteworthy it was videotaped by at least 16 independent people across the state of New York.
- The Younger Dryas Impact Event is a proposed explanation for the death of the Clovis culture and the mass extinction of North American megafauna circa 10,900 BCE. The theory proposes that a meteor impact resulted in wildfires covering most of the continent.
- The Cretaceous–Tertiary extinction event may have been caused by an asteroid impact.
Physical details:
Technically, a meteor is smaller than an asteroid. A meteor is larger than an atom, but probably not larger than 10 meters in size. An asteroid, on the other hand, could be miles long. This distinction probably only matters if gaming with astronomers, or if trying to roleplay an astronomer. If you're players are a stickler for accuracy, though, it may be important to get that right. A meteor could ruin a city, or burn down a large forest, but it would probably take a comet or asteroid to wipe out humanity.
Many large meteors move through our solar system at about 30 kilometers per second. That's pretty fast. When they hit our planet's atmosphere, they heat up to 100,000 Co or more. Particularly large and bright meteors are known as bolides, but are also sometimes just referred to as fireballs.
When a meteor hits the ground it often splashes molten metal. These blobs of metal, once cooled off and solidified, are called tektites.
Sources
See Also:
Game and Story Use
Asteroid ideas
- If you really want to threaten your campaign world with global extinction, accept no substitutes for a full-on asteroid impact. The larger asteroids would hit with more destructive force than an atomic bomb.
- Even if you survived the initial impact shockwave and it's side effects (such as Tsunami waves), the debris thrown into the air could block out the sun. The aftermath of a major asteroid hit would include global dimming not unlike a nuclear winter.
- Asteroids could be used as a Weapon of Mass Destruction by a sufficiently advanced space-faring society (or space terrorists). Using something as simple as space tug boats or a tractor beam you could divert a near earth object (or the equivalent) so that it would cross the path of a planet you were at war with. The scary thing is that in a civilization where space travel is common-place, anyone with even a modest bit of wealth could easily buy the unregulated tech to perform this doomsday terrorism. Even a small ship, given enough time and fuel, could alter the course of a large asteroid.
- Even relatively small rocks could provide an awesome (and relatively cheap) form of orbital bombardment. For example, in the TV series Babylon 5 the Narn-Centauri war ends with the Centauri Navy bombarding the Narn homeworld with asteroids using fairly simple electromagnetic mass-drivers. It is recognised, in setting, as a war crime, but also as highly effective in ending resistance on the planet's surface.
- As in Ian M. Bank's Algebraist this could be a terrifying weapon of a patient species - a strike could appear out of nowhere, decades after anyone stopped worrying about an attack, assuming that the asteroids were aimed over a long enough distance. Not only that, but if launched at around background temperature it would be entirely possible that they might not be noticed until they were very close indeed…
- Given a long enough ranged strike, the asteroids may not have even been intended for you, but for the precursors whose ruins dot the planet you colonised a century or so ago…
Meteor ideas
- Smaller meteors might not be a huge disaster initially, but could be a way for an alien virus or organism to come to Earth. Day of the Triffids, Invasion of the Body Snatchers, The Andromeda Strain, and even some Zombie Apocalypse films all riff off of this concept.
- Such impacts could also be the method for life spreading to new worlds via the Panspermia or Exogenesis theories. This could be a reason for a PC scientist to be interested in and visit an impact site (where naturally other things are going terribly terribly wrong).
- Phlebotinum could fall to earth in the form of meteors. Should the PCs see something light up the night sky, they know there will be valuables worth the expedition to retrieve them. (And probably some competing parties attempting to gather the magic rocks first.
- In a setting where every magic item has to be made from space rocks, there would be implied limits to just how common magic could be. This would be one way to let a rare powerful item exist in an otherwise low fantasy setting. All the really potent magic items need to be forged from tektite metals, of which there's a finite supply.
- In Ancient Rome, there were numerous temples that housed sacred rocks called Baetylus, including many fallen meteorites. The Romans considered these to be avatars of, or sacred to, the Gods.