Answer: Earth would become an ice-cold planet without the sun's heat and light.
Step-by-step explanation:
Without the sun's heat photosynthesis would not take place in plants. The temperature of the Earth would drop and it would not be a liveable place for numerous plant and animal species. Humans would cease to exist. The top layers of the oceans would be frozen.
Although the frozen top layers of the oceans would insulate the deep waters below, keeping them liquid for hundreds of thousands of years, they would eventually freeze as Earth moved toward a stable average global surface temperature of about -400º F. At that point, the atmosphere would have also frozen and fallen to Earth, leaving anyone left alive exposed to the harsh cosmic radiation that travels through space.
Without the light of the sun, there would be complete darkness on the surface of the Earth.