It is interesting that Genesis 1:1 says that "God created the heavens and the earth". In Hebrew, the word for "earth" is "'erets'" and it has a wide usage of meaning.....
" ʼerets, eh'-rets; from an unused root probably meaning to be firm; the earth (at large, or partitively a land):—× common, country, earth, field, ground, land..."
Genesis Chapter 1 (NASB)
In the following verses in Genesis you can see that "erets" is used for the land itself bringing forth vegetation.
When you see how this word is used in other parts of the Bible, (see the linked page) it expands the meaning somewhat.
In Exodus it speaks about the "land (erets) of Egypt." Its the same word used in Genesis 1:1 but doesn't mean the planet.
The Promised "Land" was also a geographical location, still using the word "erets".
Yet Deuteronomy 3:24 speaks of "heaven and earth" as contrasts, so clearly distinguishing between the material earthly realm and the invisible heavenly one. Context determines the meaning.
There could well be other planets out there in the universe with "earth" (land, soil) that could support life, but I believe that this "earth" is the start of the process of inhabiting the universe. Getting all the "bugs" out of the system before putting life elsewhere makes sense, because God did not create us to be robotic with no choice but to perform as 'programmed'. Part of being a parent is to be loved by our children, and having them obedient to us because they love us and trust our judgment more than their own inexperience. Yet if our children disobey us and get themselves into trouble in the process, we cannot stop the consequences of their actions from hurting them or us......all we can do is tell them we love them, but allow the experience to be the better teacher. Object lessons have so much more impact than words, especially if there is pain and suffering in the outcome. That is what humanity have been faced with since our first parents stepped outside of the limits God placed on them for their own good.
When you see how God started things off and how we lost the paradise conditions he designed us to live in, you will see in the Bible how he gets it back for us through the life and teachings of his son.
"Peace" is not just the absence of war, but a condition of the heart that comes from feeling secure and safe and loved......all of the things we had at the beginning....and the Bible says will have again in the end. Only when God's children learn to use free will unselfishly, will "God's will be done on earth as it is in heaven".....as Jesus taught us.
Just some food for thought.