There are just two ways a moon

Answer choices

1. A

   No Impact7% picked this

   The moons of some planets in Earth’s solar system were not formed primarily from the

   This is about other moons, but we only care about the story of Earth's moon.

   7%
2. B

   Correct67% picked this

   Earth’s moon consists primarily of elements that differ from those inside

   Why this is right

   This is ruling out "Way #2". We had already ruled out Way 1, that the moon was formed from an outer shell, by saying the Moon's materials don't match the outer shell of Earth. This helps us rule out Way 2, that the moon was formed when something big slammed into Earth and ejected a mass of material from inside the planet. If the Moon doesn't seem to be made out of stuff that matches the inside of Earth, then it doesn't seem to have been made via Way 2. Thus, since we've ruled out "outer shell" and "ejected internal mass", we're supporting the idea that the Earth's moon was not made out of a piece of the Earth.

   Skill tested: Strengthen · how this choice captures the argument's function is the move to repeat next time.

   67%
3. C

   Opposite7% picked this

   Earth’s gravity cannot have trapped a meteoroid and pulled it into its orbit

   If Earth's gravity could trap a meteoroid and turn it into its moon, that would satisfy our purposes nicely! That would help us argue, "the moon didn't form out of a piece of Earth; the moon is just a meteoroid that was flying by and got trapped in our orbit.

   7%
4. D

   Weakens, if Anything18% picked this

   The craters on the surface of Earth’s moon show that it has been struck by many

   The fact that the moon has been struck by many thousands of large meteoroids increases the probability that Earth might have been struck by many thousands of large meteoroids, which increases the probability of Way #2 of how the moon formed. If a large meteoroid slammed into Earth and ejected a mass of material that then became the moon, it would support the conclusion that "the moon is made out of a piece of the Earth".

   18%
5. E

   Weakens, if Anything1% picked this

   Comets and large meteoroids normally move at very

   Mainly, I wanted to avoid the irony of writing "No Impact" for an answer that is helping us assess whether comets or meteoroids have impacted the surface of Earth. This answer really does nothing, but if anything it's suggesting that since comets and meteoroids move at really high speeds, a collision with Earth would be more likely to be the violent type of collision that could eject material. Since this answer drifts toward making Way #2 seem more plausible, it's going against our purposes.

   1%