Suppose you are using the Doppler technique to look for planets around another star. What must you do?
A) Compare many spectra of an orbiting planet taken over a period of many months or years.
B) Compare the brightness of the star over a period of many months or years.
C) Carefully examine a single spectrum of an orbiting planet.
D) Compare many spectra of the star taken over a period of many months or years.
Question 2
Why are there fewer large craters on the seafloor than on the continents?
A) The seafloor crust is younger than the continental crust.
B) The oceans slow large impactors and prevent them from making craters.
C) The oceans erode away craters faster than erosion processes on land.
D) Large impactors primarily strike land masses.
E) Large impactors aim for life-forms such as dinosaurs.