It is conjectured that an enormous black hole exists at the center of our galaxy, the Milky

Question:

It is conjectured that an enormous black hole exists at the center of our galaxy, the Milky Way. Our solar system is located near the outer edge of the galaxy, some 30 000 light- years from the galactic center. Explain how astronomers might detect this black hole even though it is impossible to detect electromagnetic radiation from the galactic center due to dust and gas.