Roughly what percentage of the total mass of a galaxy is made up of luminous,or normal,matter?
A) 5 percent
B) 25 percent
C) 50 percent
D) 90 percent

Question

Quizplus · Accepted Answer

Luminous or normal matter, which includes stars, planets, gas, and dust, makes up only a small fraction of the total mass of a galaxy. The majority of a galaxy's mass is made up of dark matter, a mysterious substance that does not emit, absorb, or reflect light, but has gravitational effects on visible matter. Studies estimate that dark matter makes up around 25% of the universe's total mass, while luminous matter only makes up around 5%.

Roughly What Percentage of the Total Mass of a Galaxy