The primary way that we observe the atomic hydrogen that makes up most of the interstellar gas in the Milky Way is with ________.

Question

Quizplus · Accepted Answer

Since atomic hydrogen emits radiation at a wavelength of 21 centimeters, the primary way we observe it is using radio telescopes at this frequency. This method is known as 21-cm line emission or radio interferometry. Ground-based visible-light telescopes are not useful for observing atomic hydrogen since it is not visible in this range, and space-based ultraviolet telescopes and X-ray telescopes are not designed to detect this specific type of gas.

The Primary Way That We Observe the Atomic Hydrogen That