Final answer:
The high-speed motion of gas and stars near the Milky Way Galaxy's center is explained by the presence of dark matter
Step-by-step explanation:
The high-speed motion of gas and stars near the Milky Way Galaxy's center is explained by the presence of dark matter. Dark matter is a hypothetical form of matter that does not interact with light and cannot be directly observed. Astronomers have found evidence of dark matter through observations of the motions of gas and stars in galaxies and galaxy clusters. The faster motions and higher temperatures of gas in these regions indicate the presence of additional mass, which is believed to be dark matter.