The planet's in the middle of a glaciation, the land surface down to the fiftieth parallel is iced over solid.
"Space Viking"
Henry Beam Piper
glaciation of Wales, England, and Ireland.
"The Student's Elements of Geology"
Sir Charles Lyell
Traces of an earlier and independent glaciation have also been observed in some regions where the striation, apparently produced by ice proceeding from the north-west, is not explicable by the radiation of land-ice from a central mountainous region.
"The Student's Elements of Geology"
Sir Charles Lyell