What causes a comet to have a glowing coma and a tail?

What causes a comet to have a glowing coma and a tail?

• A. Gravitational lensing
• B. Reflection of starlight
• C. As it nears the Sun, solar heat causes sublimation of ices, creating a coma.
• D. Radioactive decay

Answer: (C)

As a comet approaches the Sun, solar heat causes sublimation of ices in its nucleus, releasing gas and dust to form a glowing coma. The coma shines because sunlight reflects off the dust and the gas is ionized by solar radiation. The solar wind and radiation pressure push this material away from the Sun, creating a tail that always points outward from the Sun. Gravitational lensing is a light-bending effect from gravity and doesn’t produce a coma or tail. Reflection of starlight alone doesn’t produce the outflow of material, and radioactive decay doesn’t drive the sublimation needed to form the coma and tail.

As a comet approaches the Sun, solar heat causes sublimation of ices in its nucleus, releasing gas and dust to form a glowing coma. The coma shines because sunlight reflects off the dust and the gas is ionized by solar radiation. The solar wind and radiation pressure push this material away from the Sun, creating a tail that always points outward from the Sun. Gravitational lensing is a light-bending effect from gravity and doesn’t produce a coma or tail. Reflection of starlight alone doesn’t produce the outflow of material, and radioactive decay doesn’t drive the sublimation needed to form the coma and tail.