What gas is found at the atmosphere that causes globalisation

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

The arrival of in the early days of europa’s existence could have formed its ocean. it is likely that the water experienced similar to earth. it is also possible that this water is retained beneath europa’s surface and in its atmosphere due to europa’s . 1.) a. precipitation b. water vapor c. icy debris 2.) a. gravitational compression b. biochemical cycling c. radiogenic heating 3.) a, gravity b. magnetic field c. heat energy for plato

What is the speed of an object at a given moment?