Earth is Precious: Its value 3,000 trillion pounds

In fact, the astrophysicist, Greg Laughlin, came up with the figure by calculating the sum of the planet`s age, size, temperature, mass and other vital statistics - and Earth came out as the most expensive.

"The formula makes you realise just how precious Earth is and I hope it will help us as a society safeguard what we have," the `Daily Mail` quoted him as saying.

Mars was only valued at 10,000 pounds, while Venus is said to be worth less than a penny. There are about 1,235 other planets in the universe, most of which weren`t given a high price tag because of their inhospitable climates.

Professor Laughlin from the University of California invented the equation, which he used to evaluate the discoveries made by US space agency NASA`s 600 million pounds Kepler spacecraft.

The planet-hunting spacecraft went into orbit two years ago and a year later Laughlin decided to create price tags for the terrestrial planets that Keplar was to discover.