Astronomers have found that some water remains on Mars in the form of ice at its north pole, unlike Earth s ice caps , during the winter this polar ice cap is covered by a layer of frozen carbon dioxide.
(this polar ice cap; is covered; by a layer of frozen carbon dioxide; T:during the winter) (Astronomers; have found; that some water remains on Mars in the form of ice at its north pole) Context(Astronomers have found,List([0, 22))):(some water; remains; on Mars)
Astronomers have found,List([0, 22))
this polar ice cap Astronomers some water
is covered have found remains
by a layer of frozen carbon dioxide T:during the winter
that some water remains on Mars in the form of ice at its north pole
on Mars