[Ref Cambridge Dictionary, Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25B Page 12-15]
According to the Cambridge Dictionary, it means “(of a planet) similar to Earth“/ “relating to the earth“.
Rightly, my next question is : What type of fog ALWAYS form over land?
Ans: Radiation fog
Radiation fog forms when the ground cools rapidly due to terrestrial radiation!