Our home planet may be the most precious place we know, but it isn't priceless. The Earth's resources and the value it offers to humans add up to some unknown, tangible cost. The species may never have to worry about buying or selling the world, but thinking of it in terms of concrete numbers can help us better understand its value. Now, as Treehugger reports, one scientist has developed a special formula that allows us to do just that.

According to the calculations of Greg Laughlin, an assistant astronomy and astrophysics professor from the University of California, Santa Cruz, the Earth is worth roughly $5 quadrillion (or $5,000,000,000,000,000). He came up with that price after gauging the planet's mass, temperature, age, and other factors that directly correlate to its ability to sustain life.

To emphasize just how valuable the Earth is, Laughlin also estimated the worth of other planets in our solar system. Our nearest neighbor Mars costs about the same as a used car at $16,000. That's a fortune compared to Venus, which he appraised at the meager value of one cent.

Laughlin doesn't expect these numbers to have applications in the real world. Rather, he hopes they will inspire people to better appreciate the only home they know. He's not the first person to put a massive, hypothetical price tag on something just for fun. The cost of the Death Star from Star Wars has been calculated at $852 quadrillion—many times Laughlin's estimate for Earth.

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