In Essence, the Kepler Mission Is Searching for Extrasolar Planets

Multiple Choice

In essence, the Kepler mission is searching for extrasolar planets by ________.

A) observing a star carefully enough to notice that it is experiencing a gravitational tug caused by an unseen planet
B) obtaining high-resolution photographs of other star systems
C) identifying spectral lines that look like what we expect to see from a planet rather than a star
D) monitoring stars for slight dimming that might occur as unseen planets pass in front of them