The Destruction of Earth

[MikMo]

I watched a show on the History Channel last night that was about the top 10 most likely ways the Earth could be destroyed (or all life on it). Number one was climate change, two was plague, three was nuclear war, number four was intelligent machines, and five was super-volcanoes. Something interesting in that segment caught my attention. There was a super-volcano that erupted around 70,000 years ago named Toba in Indonesia. The eruption was so destructive, it nearly wiped out the human race. In fact, geneticists now theorize that there may have been as few as 30 females of child-bearing capacity left alive after the event.

[MikeJones]

I wonder where the survivors where from? Like what part of the world. I figured a object hitting the earth would be ranked in the top five.

[MikMo]

Actually, when you mention that, an asteroid or comet impact was number 4. After seeing the part that interested me, I guess I became so sleepy that things just started to juxtapose in my mind.

[steer]

ya know some say the earth is just on a few thousand years old. So who really knows right? (referring to the volcanoe 70,000 years ago)

[NotSoSilentBob]

I love the way these 'scientists' just throw [censored] out there and see if it sticks to the ceiling.

[steer]

yep

[gchsajs]

I see volcano working really good. If a eruption big enough happend it wouldn't have to physically with the impact or whatever destroy the human race...but the ash and pollution would deffinately [censored] the [censored] out of man.

[MikMo]

Actually, a super-volcano, asteroid or comet impact, or a nuclear war would produce the same effect in the atmosphere, causing a the nuclear winter effect. The show stated that there is a threshold of each scenario to cause the nuclear winter. Can't remember how big the super-volcano has to be, but they said there were 20 possible candidates on Earth now that could spell doom for the human race, including Yellowstone. I think an asteroid or comet would have to be a minimum of 9 miles across to cause a world wide catastrophe. Also, it was said that a nuclear exchange of only 20 warheads would be enough for a nuclear winter.

On a similar note:

On October 26, 2028, an asteroid named 1997 XF-11 will pass Earth by about 500,000 miles, roughly two times the distance to the moon. There was speculation at the time that the object would pass dangerously close to Earth, but data collected in 1990 at the Palomar Observatory helped to dispel that rumor.

The next year, an asteroid measuring about 1,000 feet across named Apophis, will pass within 20,000 miles of Earth. The worry is that the Earth's gravity will affect Apophis and may move it into an orbit that could carry a possibility of impact on its' next pass in 2036. Although the effects of a 1,000 foot object would be negligible planet-wide, I still wouldn't want to be in the neighborhood.

Also, here's an interesting little tool I found that can calculate impact damage:

http://www.lpl.arizona.edu/impacteffects/