I am very interested in astronomy, and various topics that are related. It's really scary when you think about the huge numbers of large objects that pass directly through Earths orbital path.
(large enough to cause mass extinction).
Luckily..... space is a very big place, and absolutely perfect timing is required to bring about a direct hit
IE... the earth has to be in precisely that exact point of it's orbit around the sun to get creamed as something big as it passes through the plane. Hopefully, Earth wont experience it's own "Shoemaker-Levy" event anytime soon!! Probability suggests not...at least not soon. But what is soon on a geologic scale?? Ok... probability suggests it (maybe) wont happen during our lifetimes, or our kids, grandkids, etc, etc, etc. Within the next 10k or 100k, or million years....it's a definite reality!!
Many other events of space origin can also cause a mass extinction. Besides a major impact.....solar, supernovae, when the poles magnetic fields swap, a direct hit by too near of a gamma ray burst, etc, etc, etc. may also end all life. One thing is certain..... human life will positively end on Earth!! In my opinion, the cause will be of space origin, and we will be completely helpless to do a single thing to stop it.
Global warming, anyone?? Woaaaah... just wait until the sun swells big and red as it swallows the entire planet!! Never fear....because long before that happens, all life will have long since been killed by changes in solar output. Life on earth will have ended more than 1 billion years before the sun engulfs our planet
Our planet has endured many previous mass extinctions, and more will come and go before life permanently comes to an and on this planet.
