So, how much does the Earth weigh? We don't know for sure, but we do know it weighs a lot more than any of us! Click on image for full size (85K GIF) Courtesy of NASA

Scientists are now saying the Earth is a little lighter than we thought. The previously calculated weight is 5.978 sextillion metric tons, or 5,978 followed by 18 zeros. But the latest measurements show the true weight is actually 5.972 sextillion metric tons. So, does this mean the Earth is losing weight?

Actually, the answer is no. The truth is, one of the constants used to calculate the weight of the Earth was off. The force of gravity, shown as the capital letter G, is a little tricky to measure. Scientists have come up with many different numbers, and each one gives us a different number for the Earth's weight.

Fortunately, scientists at the University of Washington found a more precise way to measure G. And now that they have this more exact measurement, they have found the real weight of the Earth - they think. They warn that their findings may still change, so don't use the new weight in your science homework just yet.

"That is a huge embarrassment for modern physics, where we think we know everything so well and other constants are defined to many, many digits," Jens Gundlach, a physicist at the University of Washington, Seattle, said.

Who knows, maybe the Earth is losing weight!

So, how much does the Earth weigh? We don't know for sure, but we do know it weighs a lot more than any of us! Click on image for full size (85K GIF) Courtesy of NASA

Scientists are now saying the Earth is a little lighter than we thought. The calculated weight is 5.978 sextillion metric tons, or 5,978 followed by 18 zeros. But the latest measurements show the true weight is actually 5.972 sextillion metric tons. So, does this mean the Earth is losing weight?

Actually, the answer is no. The truth is, one of the constants used to calculate the weight of the Earth was off. The force of gravity, shown as the capital letter G, is a little tricky to measure. Scientists have come up with many different numbers, and each one gives us a different number for the Earth's weight.

Scientists at the University of Washington found a more precise way to measure G. And now that they have this more exact measurement, they have found the real weight of the Earth - they think. They warn that their findings may still change, so don't use the new weight in your science homework just yet.

Who knows, maybe the Earth is losing weight!

So, how much does the Earth weigh? We don't know for sure, but we do know it weighs a lot more than any of us! Click on image for full size (85K GIF) Courtesy of NASA

Do you know how much the Earth ways? Scientists think they may know. We can't put a really big scale under the Earth and measure it. So, how do scientists know what it ways?

They actually use math! One of the things scientists need to know is the force of gravity. Gravity is a very tricky thing to measure, and scientists weren't really sure what it is.

But now they have measured the force of gravity, so they also know the weight of Earth! Well, at least they think so. Other scientists have to do the experiment again before we know for sure.