Last year, the University of Strathclyde in Glasgow put forward the idea of using fleets of laser-toting satellites to deflect potentially dangerous objects away from Earth. Now, Dr. Richard Fork, principal investigator for the Laser Science and Engineering Laboratory at the University of Alabama in Huntsville (UAH), and his team have refined the idea, saying that it's not only feasible, but could handle anything up to the size of a comet.

If an asteroid 100 m (330 ft) across hit the Earth, it would be a bad day. The impact of a comet such as Halle-Bopp, which is about 70 km (43 mi) in diameter, would make for a very, very bad day. According to Fork, "[The Hale-Bopp comet] is enormous, and if it had been on a collision course with Earth we would have had only two years from the time it was first observed to the time it arrived at Earth. If the comet happened to be on track to hit us, there would have been nothing we could have done. We would have been toast."

Because of the remote, but still present, danger of such an event happening, finding ways to deflect asteroids is of great interest to scientists and engineers. The idea floated by researchers at Strathclyde University in 2012 involves sending a fleet of small satellites that fires lasers at a potentially dangerous asteroid. The purpose wouldn't be to destroy it in a spectacular Death Star-like explosion, but to nudge it into a new orbit.

Instead of one large laser blasting away at a space-going rock, several small ones from the solar-powered satellites would vaporize areas on the asteroid and this vapor and debris would act like a rocket thruster, pushing the asteroid away. The advantages of such a system are, among others, that it's cheaper than ground-based lasers or a laser installed in a large spacecraft. Since it's solar powered, the system would also require much less propellant than a single large space laser and could work at lower wattage than an Earth-based one.

David Fuller's view This may seem unimportant relative to our needs to address pressing earthly problems but they are not mutually exclusive. Science is the key to our development as a species; our ability to reduce man-made pollution, including potential human causes of climate change, and also our ability to protect the earth from rare but inevitable potential impacts by dangerous objects from outer space.

Healthy, successful and enlightened societies will address these challenges. Moreover, scientific breakthroughs create multiple and often unexpectedly valuable spin-offs. Technologies will also be driving profit growth for many of the best performing stocks.


Please note - Eoin is speaking at Fraser Asset Management's 51st Contrary Opinion Forum but will return to Comment of the Day next week.

Eoin is also looking forward to resuming The Chart Seminar, possibly in London on the 7th and 8th of November.