"Active comet" refers to a comet that is actively releasing gas and dust as it travels through space, creating a visible coma (a glowing cloud) around its nucleus. Full definition
If the orbits of these bodies are disturbed — by a passing star, for example — they return to paths close to the planets of the solar system and can become active comets. (sciencedaily.com)
And ices can be investigated, through their solid - state absorption bands, in a variety of objects - from active comets to satellites and TNOs. (tmt.org)
[116] Such ideas also apply to the close approach of Alpha Centauri or other stars to the Solar System, when in the distant future of our Oort Cloud may be disrupted enough to see increased numbers of active comets. (en.wikipedia.org)