Author Question: How do we know that galaxy clusters contain a lot of mass in the form of hot gas that fills spaces ... (Read 31 times)

yoooooman · **on:** Jul 27, 2018

How do we know that galaxy clusters contain a lot of mass in the form of hot gas that fills spaces between individual galaxies?

A) The hot gas shows up as bright pink in visible-light photos of galaxy clusters.
B) We infer its existence by observing its gravitational effects on the galaxy motions.
C) We detect this gas with X-ray telescopes.
D) We can observe the frictional effects of the hot gas in slowing the speeds of galaxies in the clusters.

Question 2

Kepler relied heavily on the telescopic observations of Galileo in developing his laws of planetary motion.

Indicate whether the statement is true or false