Many scientists believe that – more than 60 million years ago – an asteroid six miles wide struck in Mexico’s Yucatan and triggered the end of the dinosaurs. EarthSky spoke with astrophysicist David Helfand of Columbia University on the risk to people today from killer asteroids.
David Helfand: The very big ones, the ones that have global consequences, such as the one 64 million years ago that killed the dinosaurs, are very rare. They hit the Earth roughly every hundred million years or so. They do have worldwide consequences. And they will cause the extinction of a large fraction of all species on the Earth.
Dr. Helfand said that scientists today are tracking large space rocks that are potentially hazardous.
David Helfand: We are engaged in a process of systematically surveying all these rocks flying around. Of course they’re cold rocks, out there in space, and so they only shine by reflected light by the sun. And if they’re very far from Earth, that reflected signal is going to be very, very faint. Right now, the survey is pretty complete for objects larger than a kilometer in size, although there still may be a few of those out there lurking that we haven’t found yet. But for objects down to things that are say a hundred meters in size, the size of a football field or something like that, those, we’re not even close to cataloging all of them. We know in principle how to do this. It just takes lots of telescopes, lots of big cameras, and time and money.
Dr. Helfand added that tracking an asteroid is just the first step. The next step is prevention of a collision with Earth.
David Helfand: Several ideas have been proposed, such as throwing up nuclear weapons at them, or putting up a satellite that gravitationally tugs at the asteroid a little bit, so its orbit changes ever so slightly just enough to miss the Earth as it whizzes past. Those ideas are in principle doable. We understand the physics perfectly well. But they would be very expensive to implement and very little has been done to implement them.
In 2029, asteroid Apophis – about the size of a football stadium – will whisk closely past Earth. Scientists are confident it will miss, but Helfand said Apophis a good reminder that killer asteroids are out there.
David Helfand: There’s essentially zero chance of Asteroid Apophis hitting the Earth in 2029, we’ve calculated its orbit pretty precisely, and we know where its going. It’s going to miss the Earth and the moon, go between us and keep in its orbit around the sun. But it’s just, as I say, a reminder that these rocks are out there. And on a long timescale, civilization may well want to think of ways to prepare to deflect one of these, should one of them actually have Earth lined up as a target. It’s not something that people should lose sleep over when they go to bed at night. There are many other problems that the world faces that are more immediate and threatening.
Al gore says global warming is a more potent danger!
not just al gore, but many people… are you oppose to this idea? and why? i am not siding either way, but i would like to know what you think, unless their is nothing that you are infact thinking…
skye,
I think it is sad that much of our space program has been significantly defunded while billions of tax payer’s money continues to funnel into global warming research. It’s not that I bemoan the money spent on climate research. However, I can’t help but feel that public research funding has become hyper-focused on a single issue when there are equally or more important areas of research which affect our health and long term survival and deserve equitable funding.
Why smart off when unwarranted? Especially while misspelling “there”
dont believe it
i might not, but what are you basing that “dont believe it” on? who told you otherwise? are you saying it because you are opposing his political views, or are you saying it because all politiks are liars, or do you have some sort of proof otherwise?
60 million years ago, when the Earth was struck by the six miler,(a mild collison compared to the one that split the Earth up creating the moon we see),the planet Venus was not a part of our solar system. All recent data obtained from this mysterious planet – its spin, age, composition, etc, support this theory of a late comer, (recorded in the ancient texts as the ‘birth of venus’). No other planets were ‘born’. With the current mass and position of Venus factored into the system, it is not possible for a ‘global killer’, like Apophis, to strike the Earth again due to the combined gravational forces at work. Rest easy on this one. We might look at the possibility of a coronal mass ejection, like the one of 1849, as a real threat to the current civilization. A CME of that magnitude hitting the Earth today would destroy entirely, all electrical transmission lines world wide as well as all satellites in a matter of hours. This one is a real possibility. The continuing acceleration of the rate of change in the Earth’s climate will certainly thin out the human ‘hot spots’ in the near future, as agriculture becomes less predictable due to the severity of weather.
…..and you heard it from Al Gore’s brother……face it people we all are going to die sooner or later….one way or another…..when the good lord says its time…..its time
Looking for TMI? A MUST read is “Death from the Skies” by Philip Plait. You will know your astonomy after that one!
Evening;
I live in Anchorage, Alaska. Is their a site I can apply for a grant to setup a telescope watch program for the upper most northern half of our planet?.
Thank you.
Richard__
This was a good read (refering to the mighty Apophis)
I feel the same way that there are more ominous threats
that if not taken seriously could well destroy the planet
before the “Time” it takes the old boy to get here.
Humanoids that would use these verious subjects to
misdirect humanity into a web of dread in the end we
all become subservient to dictators mindless blotches
of madness consumed with the mighty quest for supremacy
Perhaps Apophis can pay “them” a visit upon his much
celebrated approach Hail!!!
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will we all die?and when?
hahahahaha………… everyone will eventually die sometime……