Which of the following events would have the greatest impact on humanity?

[Blue Fire]

I orginally posted this as a poll idea in the Astronomy Related Polls - Ideas??? thread, but I got anxious to get it out here as a real poll for a bit of fun. Maybe it should be in Chit Chat, but on the other hand, it is really astronomy related.

In any case, I think each one of these scenarious would serve to at least bring significant positive attention to astronomy if not blatently demonstrating the possible threats to Earth that so many people just don't even think about at all. I personally favor the meteor impact to have the greatest affect world wide, even though it's a potentially deadly one but not necessarily a catostrophic one.

So, I'm throwing out the ball here to see what others think.

[dmill1220]

Although the Meteor Impact would be dreadful for the city that was impacted, I would think that a Mass Coronal Ejection would have a more devastating effect on the whole World, besides the Aurora, It would wreak havoc on satellites and power grids and all other sorts of communications on a much larger scale than a 10 meter wide localized impact.
The strike would cause a major amount of attention to the sky and possible future impact of a so called Earth killer, a Coronal mass ejection of that magnitude I believe could possibly cause more damage worldwide.
Just my .02 Maybe one of the grads here has a better handle on this one than I do.
Dennis

Wouldn't a supernova that close fry us with X-rays? I just want to make sure before checking that one (I could be mistaken).

Otherwise I'd have to say the meteor impact, since I think it would level most of the city.

[dmill1220]

Hi Umop!
I believe thats not the same thing! at least not a supernova.
we have had a lot of coronal mass ejections just not anything of that magnitude in modern times.
we may have had them in the past and some have contributed the possibility of one or more mass extinction events, to the possibility of such a huge coronal ejection or a possible GRB from another nearby event.
But I may stand corrected by others with a better grasp of this subject
Dennis

[Blue Fire]

Originally Posted by umop ap!sdn

Wouldn't a supernova that close fry us with X-rays? I just want to make sure before checking that one (I could be mistaken).

Otherwise I'd have to say the meteor impact, since I think it would level most of the city.

I'm afraid that I didn't do much research myself on the choices I posted - I just kinda threw them out there as I thought of them with the idea behind them being the mere observational effects on the population that saw or witnessed them.

But upon further thought, for example as umop points out, a supernova making a bright enough showing to be viewed in the daylight would also probably have to be much closer than any other supernova we've observed in history. And, being closer would imply that Earth might indeed be bombarded with deadly concentrations of radiation.

And, I don't know how big a meteor would have to be originally to leave a 10 meter crater, but again I see that just leaving the crater would not be the only effect of it's impact. Seems like it would first have been seen as one heck of a fireball entering the atmosphere and then would have created a signigicant shock wave on impact that would result in more destruction than what it would have actually, physically hit.

Good points made by umop ap!sdn!

[Blue Fire]

Originally Posted by dmill1220

[snip]...
we have had a lot of coronal mass ejections just not anything of that magnitude in modern times.
we may have had them in the past and some have contributed the possibility of one or more mass extinction events, to the possibility of such a huge coronal ejection or a possible GRB from another nearby event.
But I may stand corrected by others with a better grasp of this subject
Dennis

Yep, a coronal mass ejection strong enough to produce such an aurora would certainly knock out all kinds of satellites and interfere heavily with ground communications of all kinds. At the very least, it would certainly get the vast majority of the world population's attention in a most negative way.

[Blue Fire]

On even further reflection, I'm thinking that a comet display visible even in daylight would get the most positive attention to astronomy. More folks would be likely to look up more often (and possibly ponder longer) and have a greater appreciation of "the heavens" in general. But the comet wouldn't necessarily carry any notions of threat with it except to those people that didn't understand what they were seeing. Of course I think there would be an awful lot of people that would panic at first, not understanding what they were seeing with a sort of "War Of The Worlds" mentality. So maybe that effect itself would bring greater awarness of both the beauty of astronomy and the possible threats to Earth by extraterrestrial objects and other astronomical phenomena like Coronal Mass Ejections and lethal radiation.

The asteroid passing harmlessly between Earth and Moon, at this point seems to have the least potential impact on humanity especially if not observed by the majority of the public. But then, on the other hand, once the media got it's hands on this event, a Very near miss might just have a huge positive impact on humanity in terms of programs out there to identify and deal with threats like this. It might just have the Best positive impact in terms of the future preparedness of the human race to deal with and survive these kinds of threats.

[dmill1220]

Hi Blue fire!
I believe that all scenarios would be rather disturbing.
And unfortunately, all these scenarios discussed here are possible.
Here is an interesting link that will let you calculate the effect of any type of impactor on the earth. Im not sure of the Algorithyms they used, or how accurate they are, but its results are quite interesting.
you choose the type of impactor, the speed and angle of trajectory, and where it strikes the earth, it will give you an idea of what could cause a 10 meter wide crater in a city, you might be surprised on how small the impactor could be to cause this scenario.
http://www.lpl.arizona.edu/impacteffects/
Dennis
PS; nice thread!

[Blue Fire]

Originally Posted by dmill1220

Hi Blue fire!
I believe that all scenarios would be rather disturbing.
And unfortunately, all these scenarios discussed here are possible.
Here is an interesting link that will let you calculate the effect of any type of impactor on the earth. Im not sure of the Algorithyms they used, or how accurate they are, but its results are quite interesting.
you choose the type of impactor, the speed and angle of trajectory, and where it strikes the earth, it will give you an idea of what could cause a 10 meter wide crater in a city, you might be surprised on how small the impactor could be to cause this scenario.
http://www.lpl.arizona.edu/impacteffects/
Dennis
PS; nice thread!

Thanks for the link! I played with the variables for some time, but was unable to adjust enough to get a resultant crater anywhere close to my original 10 meter crater example. It appears that either a much larger crater will be formed or non at all. The closest I could get was by using a hard rock asteriod with low atmospheric entry speed and high angle of impact that left of crater field due to the breaking up of the asteroid in the atmosphere.

I was surprised to find that even a 40 meter iron asteroid hitting at 90 degrees would cause a crater between .5 and 1 mile wide with not much damage to people or buildings 30 miles away. Judging from this, I'd say that an asteroid that left only a 10 meter crater "field" wouldn't do much damage to anything or anyone not too terribly close to the 10 meter area of the field except for a bit of wind and some loud noise. Hmmm.... might still get some major attention though especially if in the middle of a major city.

Originally Posted by Blue Fire

Good points made by umop ap!sdn!

Thanks!