Are there any events at interstellar disances that would affect the earth?

Can any events that happen outside our solar system affect us on earth?





A supernova would be a bright light in the sky but would it be harmful in any way? Are there any other interstellar events that might be harmful to the earth?

Are there any events at interstellar disances that would affect the earth?
solar wind is deadly, the degredation of earths magnetosphere would allow solar winds to cook the earth nearly instantly.





sources of gamma rays and x-rays include pulsars, quasars and supernova. No pulsars are that close and as far as we know, quasars are artifact from the ancient universe and nolonger exist (althought their emmited gamma rays still bounce around) A nearby supernova could wipe us out with no warning.





asteroids or comets like the one that theoretically killed off the dino's could possibly render earth uninhabitable.





i guess theoretically a rogue blackhole could eat our whole solarsystem. and we would only be able to detect it by its gravity anomilies. Even if we missed this rogue black hole by several light years, its gravity could destablize our orbit, flinging us into or far far away from our home star. (da' sun)





some people have listed galactic collision, but scientists say when 2 galaxies collide, the space between stars is so vast any physical collisions are unlikely, all orbits go up for grabs tho.





Nuclear war? i think thats probably our most pressing threat of extinction. I dont think muslums will think twice before nuking their islamic neighbors.
Reply:yea, space craft pollution (if a spacecraft were to be lost or dismembered), galaxies colliding, and that's all I could think of
Reply:1.Hypernova explosion may sterilize the planet


2.Comet impacting Earth


3.Spiral arm mid-plane crossing of the solar system: it has been postulated that this mechanism could initiate ice ages and increase the frequency of asteroid collisions with Earth.


4. Galactic collision?
Reply:If the nearest star, Alpha Centauri, went super nova, it would be, at its peak, almost as bright as the Sun in our sky. That would be a problem, heating up the planet quite a bit, but the gamma radiation would be more of a problem I think. It might wipe out all life. And the shock wave could be a problem all its own possibly. Luckily Alpha Centauri is the wrong kind of star to go super nova.
Reply:Also, while I forget the technical term, some supernovae will have abnormalities in their collapse due to an imbalance in matter, and the energy from the fusion that takes place will literally shoot out across entire galaxies (note plural). While this is rare, it would be pretty bad if we were any where near the jet.
Reply:Supernovae could be absolutely devastating if they happened very close to us. The radiation burst from a supernova is enormous and it could lead to damage of earth's atmosphere, radiation belts and cause massive extinctions in the biosphere.





Even if a supernova is not very close (500 light years), a so-called gamma-ray burst, a very focused beam of radiation and matter created in the collapse into a black hole, can devastate planets:





http://en.wikipedia.org/wiki/Gamma_ray_b...





A star which came "close" to the solar system could deflect comets in the Oort Cloud into the inner solar system and they can cause massive extinction events if they hit earth.





http://en.wikipedia.org/wiki/Oort_cloud





Hope this helps for pointers.
Reply:Supeenovae can emit dangerous amounts of cosmic radiation.