We are explorers and have discovered the world that we live on. As explorers we have sent out scouts to discover other worlds in the space beyond our blue sky.
So far we have found nothing out there that can keep us alive without protection. Some of our human scouts have gone as far as the moon and back. Others have stayed longer on an orbiting space station. We begin to realise that our long evolution on earth makes us vulnerable above the protection of that blue sky.
Our latest scouts, Rosetta and Philae, have just ended their robotic mission. They sent back data and pictures to study and admire. But it seems no life was found on that lump of rock. Even though the building blocks for life exist out there beyond our blue sky.
Only our earth, it seems, has provided that blue sky protection for us to live under. Let us do all we can to protect the earth so that we can continue to live in it's protection.