Did God create the other planets? And for what reason?
What about the other planets; why would God create other planets if not needed?
Genesis 1:16 says God created the stars. At the time this was written that would include the planets. The purpose was “for signs, and for seasons, and for days, and years.” I don’t know what that means other than the measurement of time. That may be their primary purpose.
The question asking why God created the other planets if they were not needed assumes something not in evidence—that they are not needed. Most scientists, and especially those who support “intelligent design” point out that it is the other planets that help keep earth at just the right distance from the sun to support life as we know it. They are needed.
A second answer might be that God created a number of things that are “not needed” just for our enjoyment or stimulation. Variety of foods may not be needed. It would be possible for science to develop a pill that provides all the necessary nutrients to sustain life, like in some science fiction movies. But who would take it? Most people enjoy eating because of the variety. Many enjoy food for the food’s sake, not for the nutritional value. You might even say man is “not needed.” We tend to mess up nature more than tend it. Many ecologies get along quite well until man tries to improve on them. And yet, here we are. People used to think the appendix, the spleen, and the tonsils were not needed. We now know they have functions never before suspected. The ancient Egyptians thought the brain was an extra organ with little actual function for life. So those things we think may not be needed could turn out to be the things that are most vital for our lives.