Which term refers to a ball of frozen dust and rock that orbits the sun and has a tail that glows?

• A. Asteroid
• B. Meteor
• C. Comet
• D. Planet

Answer: (C)

Comets are icy bodies that orbit the Sun and, when they get close enough to heat up, develop a glowing envelope and tails. The heat from the Sun causes the frozen material to sublimate into gas and dust, creating a bright coma around the nucleus and two tails that stream away from the Sun—the dust tail from sunlight reflecting off particles and the ion tail formed by solar wind blowing ionized gas outward. This combination of an icy nucleus in orbit and a visible tail is what makes a comet distinctive.

Asteroids are rocky bodies that orbit the Sun but don’t develop comas or glowing tails. Meteors are streaks of light produced when a meteoroid enters Earth’s atmosphere and burns up. Planets are large spherical bodies that orbit the Sun and lack any glowing tails or comas.