Then, the sunlight causes some of the comet's surface to sublime (to change from a solid like ice to a gas), and the gas reflects a lot of sunlight, causing the comet to look bright.
(the gas; reflects; a lot of sunlight) (the sunlight; causes; some of the comet's surface to sublime (to change from a solid like ice to a gas; T:Then) Context(the sunlight causes,List([6, 25))):(some of the comet's surface to sublime; to change; from a solid)
the sunlight causes,List([6, 25))
the gas the sunlight some of the comet's surface to sublime
reflects causes to change
a lot of sunlight
some of the comet's surface to sublime (to change from a solid like ice to a gas T:Then
from a solid