Gigantic boulders hurtling through space have been known to crash to Earth – that’s one of our favorite theories behind the extinction of dinosaurs 65 millions years ago. Many scientists believe a large asteroid crashed into Earth with such force it created a “nuclear winter” that gradually killed off marine animals and dinosaurs.
With all the space-monitoring gadgets available today, we really really hope mankind can avoid a similar fate.
Lately, scientists have been musing about the threat posed by smaller asteroids crashing to Earth and wiping out an entire state or triggering a catastrophe like a tsunami. The concern stems from recent studies suggesting that the risk of smaller asteroids hitting Earth and causing great damage is higher than expected.
Bigger asteroids capable of destroying species across the planet are not as big a worry because, so far as we know, none are on a course to hit Earth. There are about 750 big asteroids that measure greater than 3,300 feet in diameter. NASA is keeping a close eye on them.
There also are about 100,000 smaller ones, closer to the size of the New Orleans Superdome, between about 460 feet and one mile in diameter. They haven’t all been located. The lightning speed at which an asteroid of that size might crash into the Earth would be enough to cause widespread devastation. The most recent significant asteroid crash hit Tunguska, Siberia, in 1908 with the force of a 15-megaton nuclear bomb and created a blast area 62 miles across.
Scientists who gathered at the Planetary Defense Conference in Washington, D.C., earlier this month urged NASA to move aggressively to meet a congressional deadline of 2020 to locate 90 percent of these smaller asteroids, particularly those traveling closest to Earth and thought to be a potential threat.
NASA officials told the conference they don’t have the resources to get the job done. In 2005, Congress authorized the space agency to come up with a plan to track and deflect killer asteroids by 2020 but didn’t provide any money.
A few days after the planetary conference, the space agency presented a report to Congress underscoring its funding deficit. NASA said it needs gigantic ground telescopes or even an observatory spacecraft that can be perched on Venus to observe the space around Earth. Those devices could cost close to $1 billion, NASA said. (The United States spends roughly $1 billion every four or five days for the Iraq war).
While Congress needs to step up to the plate, there’s no reason why U.S. taxpayers should foot the bill alone. If ever there was a project that cried out for international cooperation, this would be it. Other governments should pitch in to fund the necessary telescopes and spacecraft, given that they also stand to benefit from an asteroid monitoring program.
Last month, the United Nations discussed drafting a treaty to lay out the rules for international action if a killer asteroid threatened earth. The Asteroid Action Treaty will be presented to the U.N. in 2009.
Forecasters are focusing on 2036, the year an asteroid named Apophis – after an ancient Egyptian god of evil – stands a slight chance of colliding with Earth. NASA is pondering using the gravitational force from a robotic spacecraft to pull Apophis away from Earth, sending an unmanned spaceship to collide with it, or other means to divert it.
At the planetary meeting, conference chairman William Ailor suggested that more countries should get involved in the effort to protect Earth from Apophis. He mentioned that the European Space Agency is considering a mission called Don Quixote to test ways to deflect an asteroid. “Should one nation, the United States, be responsible for the entire planet?” Ailor asked, a rhetorical question if ever there was one.
We hope the U.N. will approve the Asteroid Action Treaty and that it will trigger a serious effort to protect Earth from a threat that we, like the dinosaurs, can barely imagine.