A collection of gas dust which appears as a bright ball of light in the sky with a glowing tail is called

A comet is a small celestial body primarily composed of frozen gases, dust, and rocky material [c2][t4]. Often described as 'dirty snowballs', comets originate from distant regions like the Kuiper Belt and Oort Cloud [c5][t4]. As a comet approaches the Sun, solar heat causes its volatile ices to sublimate, releasing gas and dust that form a glowing cloud called a coma and a distinct, bright tail [t1][t2]. This tail, consisting of an ion tail and a dust tail, always points away from the Sun due to solar wind and radiation pressure [t2][t3]. In contrast, stars are massive spheres of plasma undergoing nuclear fusion [c3], constellations are patterns of stars, and galaxies are vast systems of stars and dark matter [t6]. Therefore, the description of a bright ball of light with a glowing tail specifically identifies a comet [c1][t5].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > UPSC Prelims 2011] What is difference between asteroids and comets? > p. 36
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > UPSC Prelims 2011] What is difference between asteroids and comets? > p. 35
3. [3] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 2: The Solar System > Comets > p. 33
4. [4] https://sathee.iitk.ac.in/article/physics/celestial-bodies/
5. [5] https://spaceplace.nasa.gov/comets/en/