CANBERRA - The good news is that Earth is far less likely to be devastated by a comet than previously thought.
The bad news is that you still have more chance of being atomised by a space rock than winning Lotto.
Australian astronomer Dr Paul Francis said there were farfewer comets in our solar system than previously thought, lengthening the odds of a strike on Earth.
But you still have a 3,500,000-1 chance of meeting your maker via asteroid, compared with 3,838,380-1 odds of picking all six NZ Lotto balls.
Francis said computer simulations and data from both amateur observers and the US military's Near Earth Asteroid Research Project showed there were seven times fewer comets in our solar system than previously thought.
In theory, this means we have a much better chance of avoiding a devastating collision with large chunks of space debris.
However, the latest issue of journal Nature reported a 1000-tonne comet exploded above Antarctica last year with the force of the atomic bomb that levelled Hiroshima.
And astronomers remain worried by the 320m asteroid 99942 Apophis that is expected to pass within 32,000km of Earth in 2029 - dangerously close in space terms.
No one can yet count precisely how many city-or planet-devastating comets may be coming our way.
But the prospect is still real enough for scientists to be working on ways to destroy or deflect large objects before they hit Earth.
But because of the new findings Francis, of the Australian National University's School of Astronomy and Astrophysics, said the odds were now much longer.
"I calculate comets capable of destroying a city only hit the Earth once every 40 million years or so.
"Big continent-busting comets, as shown in the film Deep Impact, are rarer still, only hitting once every 150 million years or so.
"So I don't lose sleep over it - but statistically you are still more likely to be killed by a comet than to win the Lotto jackpot."
