What are asteroid sized objects that develop a huge bright tail when they come near the sun?

Asteroid-sized objects that develop a bright tail when they approach the sun are known as comets. Unlike asteroids, comets are composed largely of ice, dust, and rocky material. When they near the sun, the heat causes the ice to vaporize, creating a glowing coma and a tail that always points away from the sun due to solar wind. This distinctive tail can be quite striking, making comets visible even from Earth.