The composition of a planet's atmosphere be measured during a transit by analyzing
A)the excess absorption of starlight at specific wavelengths.
B)the excess emission of starlight at specific wavelengths.
C)the length and depth of the dip in light during the transit.
D)the amplitude and period of the star's motion.
E)the wobble in a star's position on the sky.

Question

Quizplus · Accepted Answer

When a planet transits in front of its star, it blocks some of the star's light. By analyzing the spectrum of the star's light during the transit, astronomers can detect the excess absorption of specific wavelengths of light, which reveals the composition of the planet's atmosphere. This method is known as transit spectroscopy.

The Composition of a Planet's Atmosphere Be Measured During a Transit