Del Boy's Robin Reliant would provide more than enough energy to save theworld from a deadly asteroid impact, according to new research. DickAhlstrom reports.
Earth sails through space like a target in a shooting gallery. Asteroids and comets whiz past, coming close enough to pose a real threat of wiping out life as we know it.
Yet an earth scientist at Imperial College London believes we could easily save ourselves from extinction, provided we discover any potential impactor early enough. Not only that: it wouldn't take anything particularly powerful or dangerous to turn a billion tonne asteroid away from us.
To prove his point, Dr Matthew Genge of ICL proposed that an 850cc Robin Reliant, the three-wheeled car favoured by Del Boy in Only Fools And Horses, produced more than enough energy to save us all - and he had the figures to prove it.
The 1978 model weighed 650kg and could accelerate to 60 m.p.h. in a rather pedestrian 16 seconds. Its little engine produced a thrust of about 1,083 newtons - a measure of force - Genge last week told the British Association's annual festival of science, in Salford.
This seems impossible odds against a proposed billion-tonne asteroid, so Genge decided to find how many Robin Reliants would be needed to do the job. School-level physics was all he required to show that a single Reliant could prevent catastrophe in just 75 days. "A Robin Reliant could save Earth, but a Mini could do it faster," he added.
He had made several assumptions, including that we would expect to discover this large asteroid at least 10 years before it could hit us. In that case it would be necessary to change its speed by just 0.7 centimetres a second to make it sail harmlessly past us.
The plucky Reliant could provide a push against the asteroid of a billionth of a metre a second, not much but enough to change the asteroid's path 10 years hence.
So does that mean we can now scoff in the face of danger? No, admits Genge. All we know for sure is that some time in the future - with luck a distant future - a wandering asteroid will hit us. "The impact of the earth being hit by a large asteroid is about the only thing that could wipe out life on the planet."
And although the newly discovered asteroid that scared everyone earlier this month was quickly shown to be a false alarm, the "big one" with our name on it may already have been found, says Genge. Scientists got a long look at what was christened asteroid (29075) 1950DA - discovered in February 1950, then rediscovered in December 2000.
This nasty beast, about 1.1 km across, is now rated as one of our greatest impact hazards. Analysis of its orbit has shown there is a one-in-300 chance 1950DA will hit us, with dire consequences for life as we know it.
The good news is that its close fly-by - or impact - isn't expected until March 16th, 2880. It shows, however, that space debris is a genuine risk, says Genge. "It is possible the countdown has already started with 1950 DA," he adds. "Maybe that is a good thing: nobody is panicking."
And there are things that can be done in the meantime. One of them is to continue a worldwide effort to identify all near-Earth objects (NEOs) with diameters of more than a kilometre. "Impact hazards are minimal so long as governments continue doing what they are doing," says Genge, scanning the skies with telescopes capable of spotting NEOs.
There is general agreement that this work has helped identify about 700 of the estimated 1,000 NEOs of a kilometre or larger anywhere near our orbit. By 2008 this should stand at about 900.
Research should also continue to find ways to impart the small amount of force needed to divert an asteroid while it remains a long way off. With 10 years to spare, simple expedients such as painting one side of an asteroid could help divert it, as could a "mass driver", a machine that pitches objects off of an asteroid's surface, thus imparting a tiny force.