>Explain whether life could exist on other
planets or moons in our solar system.

The direct answer to the question "Can there be life..." is that there is potentially a non-zero possibility. Testing the null hypothesis, that there "cannot be life" is quite difficult. Evidence for and against both positions exists. However strong the arguments for life, space provides many harsh environments, yet we know deep in our oceans at hydro-thermal vents or in volcanic geysers there is life. Seeing volcanism on other worlds at least provides a necessary energy source. But the null hypothesis has a fatal flaw. We know of one location where there is life, and we discover over and over again that its conditions are not very special in the Universe. The famous Drake equation goes much further, to single out intelligent life that still exists today and wishes to communicate. But in very sad news for the null hypothesis, even it is non-zero.

layer a is the exosphere and layer b is the thermosphere.   is the answer i think but i hope this .

thermal energy is the answer