Which celestial object is characterized by jets of gas and dust, forming long tails when near the Sun?

The object characterized by jets of gas and dust that form long tails when near the Sun is a comet. Comets are composed primarily of ice, dust, and rocky material. When they approach the Sun, the heat causes the ices to vaporize, creating a glowing envelope of gas and dust around the nucleus known as a coma. The solar wind then interacts with this material, resulting in the formation of one or more tails that point away from the Sun. This distinctive feature is what sets comets apart from other celestial objects.

Meteoroids, on the other hand, are typically fragments of asteroids or comets and do not develop tails. Asteroids are generally rocky bodies that do not exhibit the gas and dust phenomena associated with comets, while planets are large bodies that orbit stars and do not produce tails like comets do. Thus, the unique behavior of comets when they approach the Sun is what makes them the correct answer in this context.