But what about the thousands of larger rocks flying in space? Take, for instance, the one known as Ceres, which is about 600 miles [1,000 km] in diameter! And there are about 30 other known rocks with a diameter greater than 120 miles [190 km]. These larger rocks are actually minor planets. Scientists call them asteroids.

What if one of these asteroids were to crash into the earth? This apparent threat is one important reason why scientists study asteroids. Although most asteroids orbit in a belt between Mars and Jupiter, some tracked by astronomers actually cross the orbit of the earth. The threat of a collision is reinforced by the existence of huge craters such as the Meteor Crater (also known as Barringer Crater) near Flagstaff, Arizona, U.S.A. One of the theories for the extinction of the dinosaurs is that a large impact altered the atmosphere and plunged the earth into an extended period of cold weather through which the dinosaurs could not survive.

Such a catastrophic collision today would likely destroy mankind. However, the Bible indicates that “the righteous themselves will possess the earth, and they will reside forever upon it.”​—Psalm 37:29.

[Box on page 24]

Rocks From Outer Space

Asteroid: Also known as a planetoid or a minor planet. These extremely small planets travel in an orbit around the sun. Most have irregular shapes that may indicate that they are fragments of once larger objects.