The composition of the solid surfaces of planets and satellites (moons) that do not have substantial atmospheres can be found by:
A)measuring the thermal emission from the surface at several wavelengths in the microwave and infrared regions of the spectrum.
B)comparing the spectrum of the sunlight reflected from the surface with the spectrum of direct sunlight from the Sun.
C)comparing very broad absorption features in their spectra with spectra of known substances on Earth.
D)measuring the wavelengths of narrow absorption lines in their spectra.

Question

Quizplus · Accepted Answer

Comparing very broad absorption features in the spectra of planets and satellites with spectra of known substances on Earth is the best way to determine the composition of solid surfaces. This is because different elements and compounds absorb light at certain wavelengths, causing broad absorption features in their spectra. By comparing these absorption features with spectra of known substances on Earth, we can determine the composition of the solid surface. The other options (measuring thermal emission, comparing reflected sunlight, and measuring narrow absorption lines) are useful methods for studying planetary atmospheres, but they do not provide as much information about the composition of solid surfaces.

The Composition of the Solid Surfaces of Planets and Satellites