Given that there’s bugger all you can do about it, and that a major impact with earth could put the scope of potential earthly nuclear warfare into the category of small town fireworks, you could be forgiven for averting your eyes from the stars and reaching for the sauv blanc.

But some scientists and US congressmen are taking ‘asteroid impact avoidance’, as it is now termed, very seriously. Chief among them are congressman is George E. Brown, who sponsored a successful bill to investigate what can be done.

Says George in a US Air Force journal: "If some day in the future we discover well in advance that an asteroid that is big enough to cause a mass extinction is going to hit the Earth, and then we alter the course of that asteroid so that it does not hit us, it will be one of the most important accomplishments in all of human history."

In 2008 Congress funded the National Research Council to make recommendations on NEOs, or ‘Near-Earth Objects.’ George E. Brown and others are worried because NEOs have the potential to bring down the curtain on the human race and our polluted soccer ball.

The National Research Council in Washington recently delivered its final report ‘Defending Planet Earth: Near-Earth Object Surveys and Hazard Mitigation Strategies.’

It explains how mere earthlings ‘mitigate’ an asteroid or a comet hurtling towards earth that could be a kilometre wide. One of the strategies proposed is a study into a ‘nuclear deflector’ spacecraft.

In layman’s terms, a large nuclear bomb is fired and exploded at the incoming asteroid, which might then be vaporised or at least knocked off course, hopefully saving Mother Earth.
 
Spaceships and more orbiting telescopes would have to be built. One estimate for just one extra 0.5 metre infrared telescope ranged from “between $140 million and $1.8 billion.” 

The National Research Council has given a ‘floating’ estimate of potential research costs. Congressmen can pick the cheapskate $10 million annual level of funding to continue existing research, $50 million annual funding to achieve the goals set by congressman Brown, or the $250 million annual bells-and-whistles funding if all this research continued for a decade.

But this doesn’t get you much beyond research. The cost of the spacecraft of course is more.
Still, President Obama recently canned the loony idea of another US stroll on the moon, so maybe there’s still funding in the bottom drawer.

In its most recent report, the National Research Council pointed out that earth is continually bombarded by cosmic objects and, luckily, most are small and are harmless. "Some, however," the Council says "are large and cause considerable harm. Evidence of these collisions, large and small, is abundant...

"Even objects only 30 metres in diameter can cause immense damage. The cosmic intruder that exploded over Siberia in 1908 may have only been a few tens of metres in size; yet this explosion severely damaged a forest of more than 2,000 square kilometres."

The Tunguska explosion in Siberia in June of 1908, the subject of Big Bang in Tunguska, is enough for habitual worriers to dine out on fingernails forever. The Tunguska blast reportedly had the force of more than 1,000 Hiroshima atom bombs.

We see a parade of scientists giving their theories about the Big Bang (most of them in disagreement) and the producers have thrown in a host of fables and myths to add spice.

But keep reminding yourself that the Tunguska Big Bang did happen. And if you're not yet worried about hurtling Near Earth Objects just remember what happened to the dinosaurs!