But that doesn't mean the Earth has become unusually active.

"We all, every one of us, left because we feared what Earth had become."

And Earth has become less than a legend.

However, the corporation gave up after realizing how toxic Earth had become.

Earth will become like Heaven, and joy will be universal.

Well, Earth became radioactive, or at least its crust did.

After all, Earth has become one giant mental hospital.

Men traveled to Mars for many reasons, and one of them was that Earth had become too uncomfortable.

It is a bleak vision of the future when the Earth has become totally sterile.

How much more distanced might Earth become in three hundred more years?