List Of The Potentially Hazardous Asteroids (PHAs):

just perusing around looking for info about PHA, i came across this page. thanks to the fine folks at harvard, here is a list of "Potentially Hazardous Asteroids (PHAs)"

PHAs

interesting to see "Apophis" at the top of the list on this page:
Close Approaches to the Earth

i was amazed to see how many were charted and how many were being discovered on a daily basis. gives a little perspective.

Just remember, that list order (closeness) may not tell the whole story.

Imagine a troublesome, but slightly drunk bee flying at your head as you walk along the road.

If he misses you with a direct buzz, but is 'caught' and re-attracted, and swings around you in an elongated orbit, he may end up with one or more additional tries, when it swings around.

Of course all this time your head will be moving - more or less at a constant acceleration (you don't notice him).

Untill the asteroid gets out of the area and the capture is broken, any of them could get another close pass. Unlike even drunk bees, asteriods and comets have no intent, that I'm aware.

Now, I've only seen a couple orbital animations, and those showed other passes in the same event, but they were not very close.

I'm not sure if the prognostication programs are able to get that kind of detail (beyond one or two oscillations, or Earth-Object dances).

So one that's within capture range (depends on the size of the object and the closeness of the pass), after a first pass, may end up being that drunk bee that gets lucky, later.

I don't know if 10 Earth-Moon diameters is close enough (Apophis) to get a capture - don't know the size.

Just a seat of the pants; 2 cents.

If there's one that approaches from a bad angle that had not been plotted yet, it could be a surprise.

Originally posted by Badge01
Unlike even drunk bees, asteriods and comets have no intent, that I'm aware.

That's what you think! The Bugs of Klendathu beg to differ.



Sorry, couldn't resist

You know, I think if a meteor were to hit, there'd be no advanced warning. Unless it was discovered by amateur astronomers who put the word out on the internet. It's too great an opportunity for population reduction by The Powers That Be to pass up.

Just my conspiratorial mind thinking up silly scenarios.