Planetary transits of exoplanets are rare because
A) most extrasolar systems are not seen edge- on.
B) our telescopes are not powerful enough to detect them.
C) most stars are too bright for us to detect a planetary transit.
D) the Earth's atmosphere interferes with our observations of transits.
E) most exoplanets are smaller than Pluto.

Question

Quizplus · Accepted Answer

Planetary transits of exoplanets are rare primarily because most extrasolar systems are not aligned in such a way that their planets pass directly between their star and the Earth (seen edge-on), which is necessary for us to observe a transit.

Planetary Transits of Exoplanets Are Rare Because