What is a chunk of ice and dust that travels in a long orbit around the sun called?

A chunk of ice and dust that travels in a long orbit around the sun is called a comet. Comets are composed primarily of ice, dust, and rocky materials, and they often originate from the outer regions of the solar system, such as the Kuiper Belt or the Oort Cloud. When they approach the sun, the heat causes the ice to vaporize, creating a glowing coma and sometimes a tail that is characteristic of comets.

This definition distinguishes comets from asteroids, which are primarily made of rock and metal and do not have the same icy composition. Meteoroids are smaller celestial objects that can become meteors when they enter the Earth’s atmosphere, but they are not characterized by the same icy and dusty composition. Planets, on the other hand, are larger celestial bodies that orbit stars and do not fit the description given in the question. Thus, the correct term for a chunk of ice and dust in a long orbit around the sun is indeed a comet.