Skip to comments.Earth’s gravity may lure deadly asteroid
Posted on 04/18/2005 7:21:31 AM PDT by aculeus
A HUGE asteroid which is on a course to miss the Earth by a whisker in 2029 could go round its orbit again and score a direct hit a few years later.
Astronomers have calculated that the 1,000ft-wide asteroid called 2004 MN4 will pass by the Earth at a distance of between 15,000 and 25,000 miles about a tenth of the distance between the Earth and the Moon and close enough to be seen with the naked eye.
Although they are sure that it will miss us, they are worried about the disturbance that such a close pass will give to the asteroids orbit. It might put 2004 MN4 on course for a collision in 2034 or a year or two later: the unpredictability of its behaviour means that the danger might not become apparent until it is too late.
As a safety precaution, some experts are calling for 2004 MN4 to be tagged with a transponder that would constantly radio its position. Scientists hope that this would provide enough warning to allow emergency action if necessary, possibly by diverting the object away from the Earth.Other instruments on the probe could provide information about its composition.
Benny Peiser, from Liverpool John Moores University, who is an expert on asteroid hazards, said: We dont know what that asteroid is made of and that might influence the way its affected by the Earths gravitational pull. There are other close approaches, in 2034 and 2035. In all likelihood it will produce an orbit that will not intercept the Earth, but we dont know.
The asteroid is big enough to cause damage on a regional scale, with an expected impact equivalent to a 1,000-megatonne explosion. It was discovered last June and its orbit plotted in detail by December. Startled astronomers calculated at one point that its chances of a direct hit on Friday, April 13, 2029, were 1 in 38. But additional calculations have set those fears to rest. The asteroid is now expected to miss but come close enough to be below the altitude of TV satellites. It should be visible as a rapidly moving point of light.
Brian Marsden, of the Harvard-Smithsonian Centre for Astrophysics in Cambridge, Massachusetts, expects the close encounter to increase the frequency of the asteroids orbit, creating the possibility of further close encounters every five to nine years.
An interceptor mission is feasible and Dr Peiser said that an opportunity would arise in 2012, when 2004 MN4 will be ten million miles from Earth. Thats not a big distance as far as space missions go, he said.
This is most likely not the object with our number on it, but one day we will have to address this question and well need the technology. A transponder mission should not be too complicated or costly, and would provide a lot of vital data.
Copyright 2005 Times Newspapers Ltd.
ya beat me by 4 seconds :-)
and here in a couple days we will find out that even these fears are without merit.
it does need to be watched however....
Great. Just about the time I retire, too...
Bush must have thought this up right after he planed the tsunami.
So this means we don't need to fix Social Security?
Should be quite a show looking out of my nursing home window.
This sounds far-fetched, but I'm no rocket scientist.
Chicken Little is getting over on his future SS contributions
I love this site
Ok Cubs fans you've only got 29 more years left to win a World Series.
Yeah - put a radio beacon on the darned thing, just in case it gets lost!
women and children hit hardest
This is hardly a huge asteroid. Big enough to reach the ground and do significant local damage, but not enough to panic about.
Looks like I'll need burn my personal leave before 2034 :}
Write your congressman and demand more restrictive gravity control laws NOW!
Bah, who cares. We can get Bruce Willis and his wacky deep-well drilling team to go take care of it. This time I hope they leave Aflek on the thing to set off the nuke, though.
It won't get captured, but if it passes close enough, earth's gravity well could change its course slightly. The final effect of that course change cannot be predicted until we know exactly how close it passes.
That seals it, no need to change social security, the earth will be destroyed anyway!
April 13, 2029?
Damn, that'll be my 42nd birthday!
Gravity is obviously too dangerous. It should be banned.
We must elect Hillary Clinton as President.... she will save us.
The headline reminds me of SUV headlines. Maybe we can lure the asteroid away from us bu providing an incentive. If we only knew what asteroids liked best. Female asteroid?
>How does the asteroid lose enough kinetic energy to be captured by Earth's gravitational field?
The asteroid is currently in *solar* orbit. A near encounter with Earth would slightly deflect the asteroids orbit, by gravitationally tugging it to one side. It would still be in a solar orbit, just a slightly different one. However, the change in orbit cannot be accurately calculated until we know *exactly* how close it will pass by the Earth/Moon system (the moon will *also* tug slightly on the asteroid).
And with timescales of 30+ years, you also really need to factor in Jupiters gravitational effect as well.
Orbital mechanics is based on some pretty simple equations... when you only have two bodies. But in this circumstance, there are at least 5 that need to be accounted for. Extremely complex, requiring lots of computer power and *very* precise observations.
Yeah, OK, but it will be a "lossless" encounter, won't it? Maybe not.
Are they concerned that it will exchange momentum with the earth in a way that slows it down (as opposed to speeding it up as happens when we use Jupiter's gravitational field to shoot satellites out to Neptune, etc.)?
Thats what the dinosaurs said.
Aha! They just want an excuse to use tax dollars to "tag it for safety", oh, and by the way, study the composition.
Why hasn't Jupiter gobbled this one up yet?
Billions of years, HAH!
Agreed. A many-body problem has no analytic solution - it requires zillions of calcs to find a best solution.
But by 2029, your wristwatch will be able to do those calcs.
This asteroid would be a local disaster if it hit, not a global one; the articles on it generally note this but it's interesting that people really don't seem to notice.
It's only 1000 ft across? Ummmm, maybe I'm missing something here but if it's coming so close, why are they going to tag it with a radio transmitter and not just blow the thing apart, thereby nullifying any risk at all?
> But by 2029, your wristwatch will be able to do those calcs.
Wristwatch? No, those will no longer exist. The brain-chip will simply display a heads-up display directly onto your retina (giving you the time in all time zones, along with your exact location), do your taxes, calculate orbital trajectories two millenia out, and project the fourteen most-likely-successful pick-up lines to the four-breasted genetically modified hottie in the corner.
Of course, if there's a "President Hillary" between now and then, that chip will *broadcast* your position, will modify your behavior, make you feel happy whenever Madame President appears (which will be every ten minutes) and will be mandatory.
We're not doomed. We need to catch it. Who ever catches it will be rich I tell you. RICH!
> Why hasn't Jupiter gobbled this one up yet?
Because the asteroids orbit goes nowhere near Jupiter.
Well it could change earth orbit and put us closer to the sun and cause globel warming.
What difference does it make? We are all suppose to have died from the Avian Flu before then.
If I've got a bad idea, perhaps someone knowledgeable could explain why.
When gravity is outlawed, only.................
"It might put 2004 MN4 on course for a collision in 2034..."
I'll be 88. Now I have something to look forward too.
> why are they going to tag it with a radio transmitter and not just blow the thing apart, thereby nullifying any risk at all?
Because we're not real clear even yet on how to blow apart a 1000-foot asteroid of unknown composition. And without knowing exactly what it's trajectory is, blowing into pieces might well take a 1000-foot asteroid that was going to miss Earth and turn it into several 400-foot asteroids that WILL hit Earth.
Thanks for the ping!
So Jupiter hasn't been the solar system vacuum for billions of years?
Those comets and asteroids have been awfully plentiful on our short life spans. Shumaker-Levy would have been life ending if it were to have hit earth. In our very lifetimes.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.