Erie's Paul Siple was a polar explorer and geographer who accompanied Richard Byrd to the Antarctic. Wind chill was first calculated by Siple in 1945.

In subzero winds, hypothermia announces itself in small, easy-to-miss ways. Here’s what one Nat Geo Explorer does to combat it in some of the coldest places on Earth.

There’s no mistaking Jupiter in the sky these Shamokin winter evenings, rising in the southeast as evening twilight ends. In ...