comet
Definition
A celestial object consisting of a nucleus of ice and dust that, when near the sun, develops a tail of gas and dust pointing away from the sun.
Español Objeto celeste que consiste en un núcleo de hielo y polvo que, cuando está cerca del sol, desarrolla una cola de gas y polvo que apunta lejos del sol.
Example
"Halley's Comet appears every 76 years."