What if Earth and the Moon Were Hit by Twin Asteroids?
ES2506  Is Earth a Target?

The moon's surface is covered with craters, an obvious sign of asteroid impacts. As Earth occupies the same region of space as the moon, it seems unlikely that Earth has escaped collisions with large asteroids. Below, Earth and the moon are shown at the same scale. How do they compare as targets for asteroid collisions?

  !   Use the ruler tool to measure the diameters of the moon and Earth. Use your measurements to answer question 3 below.



Earth and the moon are spheres, but to an incoming asteroid they appear as circular targets. Find the area of each target using the formula Area =πr2, where π is 3.14 and r is half the diameter you measured.

3. Calculate the "target area" of Earth and the moon. How many times larger a target is Earth than the moon? What does this say about Earth's chances of being hit by an asteroid comapred to the moon's chances?


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