Nowdays,with Russian prospering the laboratory is humming with top secret work.

Obtaining permission to enter proved impossible.But Vadim Simonenko,the deputy scientific director,and experimentalist Nikolay Voloshin agreed to meet at a sanatorium in nearby Dalnyaya Dacha.In a cool,dim,and empty dining hall,Voloshin opens a bottle of cognac,and over salmon canapes,and cold cuts,and sliced cucumbers,the two weapons scientists discuss how their bomb could save the world.In Edward Teller is the father of the hydrogen bomb,Simonenko is the father of the asteroid bomb.In the mid-1960s the superpowers dreamed of using their nuclear arsenals for peaceful purposes,such as leveling mountains and digging canals.Simonenko,a new recurit to the lab,was asked to study the effect of a torpedo-shaped charge that would explode laterally,ideal for earthmoving.It occured to him that such a device could also be used to deflect an object in space.He told his boss,who laughed and ordered the eager young physicist to get back to work.Though nuclear excavation never became a reality,Simonenko went on studying nuclear asteroid deflection.He and Voloshin concluded that the best way to deflect an asteroid up to a mile or so wide would be to detonate a nuclear charge nearby.The intense radiation would fry the surface,driving off a sacrifical layer of rock.The expanding vapor would act as a rocket motor,nudging the asteroid onto a new trajectory.For a smaller,Tunguska-size rock,Simoneneko says,it would be simpler.We vaporize it.



Simonenko has a brother-in-arms in nuclear physicist David Dearborn of Lawrence Livermore National Laboratory in northern California.Dearborn's day job is determining whether the aging weapons in the U.S. nuclear stockpile are reliable.In his spare time,he ponders asteroid defense.He,too,favors a stand off nuclear blast.No too close-then the blast is too intense.and things shatter too much.And not too far,or you don't get enough energy.Although it may be technically straightforward to dust off a few warheads and sling them at an asteroid,deciding whether to press the red buttom-and which nation gets to press it-could be excruciating.First,the nation with its finger on the trigger would have to withdraw from the outer space treaty,which bans the use of nuclear weapons in space.But if catastrophe looms,says Dearborn,people would really have to say,Can we be brighter than the dinosaurs?Apophis may pose that the first real test of our collective intelligence.For now,scientists can give only a range of probabilities for its future trajectory.As it swings past Earth in 2029,ducking under dozens of high-flying communications and spy satellites and appearing as a bright star lumbering across the night skies over Europe,there's a slim chance that Apophos will pass through a keyhole.In this narrow corridor of space,maybe a few hundred yards wide,Earth's gravity would deflect the asteroid just enough to put it on a certain collision course with our planet on the next pass,in 2036.The odds that Apophis will pass through this fatal corridor are currently estimated at 1 in 45000.Continued tracking will almost certainly deliver an all clear a few years from now.If now,we might have to wait until weeks after its close approach in 2029 to learn whether Apophis has squeezed through a keyhole,leaving us precious little time to avert calamity in 2036.In the prophesies of the Hopi of the American Southwest,the arrival of a spirit called Yellow Star Kachina will herald the end of the world.When Hopi elder heard about Apophis in 2004,they worried that Yellow Star Kachina was on its way.Carolyn shoemaker tried to reassure them that it was not.Let's hope she was right.