View Full Version : Discussion: Asteroid Risk Lowered

2003-Sep-02, 06:03 PM
SUMMARY: When Asteroid 2003 QQ47 was discovered last week from a tracking system in New Mexico, astronomers predicted that it could strike the Earth in 2014. Astronomers have now made 51 observations of its orbit and determined that the chance of it hitting the Earth are 1 in 909,000 and additional observations will probably reduce this possibility to zero. The space rock is estimated to be 1.2 km across and traveling at a speed of 30 km/second. If it did strike the Earth, it would cause widespread destruction across an entire continent, releasing the same amount of energy as 350 billion tonnes of TNT.

Comments or questions about this story? Feel free to share your thoughts.

Al in Virginia
2003-Sep-02, 09:28 PM
Okay, speaking hypothetically: After tracking this asteroid and making 51 observations the astronomers discover that it will indeed collide with earth in the year 2014 I would like to know how soon would they be able to predict the date and location of impact. Asked another way; once they determine exactly when and where it will hit they can begin to evacuate. How much time will we have to get everybody out of the way assuming all countries are equal and everybody follows the drill and does not panic?

My gut feeling tells me (and I am just guessing): given the current level of tracking ability it will be at least a decade (sometime in 2013) before they can pin point the strike area with, say, 99% certainty. How close am I to the mark? Would it be possible to know ten years in advance EXACTLY where it strike on the surface? Do these asteroids travel at a consistent speed? Do we understand how the gravity of the moon and other bodies will effect it's trajectory as it gets closer?

2003-Sep-03, 04:09 AM
I've had several people mention this story to me... typically the press have been quick to report the prediction of a possible asteroid strike in 2014 and slow to cover the follow-up story. After all, the odds of 1 in 909,000 aren't very exciting to the media.

But then, as someone jokingly said to me tonight, the odds of winning the lottery here in the UK are 1 on 12,000,000 and someone wins that almost every week!! :P


2003-Sep-03, 03:31 PM
I just watched the news here (9:00 MST or about 3:00 GMT) and they are still talking about the possible strike in 2014--no mention of the downgrade in odds due to the better observations of it's orbit.

Seems like another instance of the news media crying wolf.

To try and answer some of Al's questions, the orbital observations would allow for the date and time of impact to be narrowed down to a fairly small window--which also means a very big area of danger on the planet. The absolute certain time and place would not be determinable until the object was much closer than it is now.

As for the possibility of evacuating, how do you evacuate a continant? Where would you go? An asteroid that is 1 1/2 km in diameter would cause significant destruction over a 3000 km or more radious, and the after effects would be global.

In addition, a significant area of the planet would likely see a rain of fire from the debris of the strike re-entering the atmosphere. If it landed in an ocean, the area affected would encompass many millions of people in coastal areas surrounding the ocean basin struck. The tzusamis caused by an object this big would reach heights of 1000 metres or more, travelling at speeds of 600 kph--as fast as a jet plane.

There are several good simulations of an asteroid impact available on the web, I even seem to recall Universe Today carried an article on one not all that long ago. The movie "Deep Impact" also has a good simulation of a 1km or so sized object striking the Atlantic ocean.

Fraser, perhaps you could link that article?