Life in the Universe
Astronomy has reached the point of being able to state conclusively that the known universe contains a greater number of stars than the number of grains of sand on all the Earth’s beaches and in all of its deserts.
The age of the universe has been definitively set at 13.7 billion years ago. The age of the Earth is around 4.5 billion years. Life first formed about half a billion years later and the human species is about 3 million years old. Agriculture began about 10,000 years ago. The human population size exploded from about 1 billion to just over 7 billion in a little over two hundred years. That rapid expansion coincided with the industrial revolution and the rapid exploitation of cheap, high energy density, fossil fuel resources.
Astronomy has discovered planets circling other stars and has even reached the point where it can estimate their sizes and distances from their mother stars.
It is logical to conclude that planets circling stars must be a very common occurrence around the vast universe. Based on knowledge of our solar system, planets too close to the star are too hot to support life and those too far away are very cold and receive substantially less radiation from their star, so probably cannot support more than the most primitive life forms, if any at all. There is a “sweet spot” at just the right distance, a habitable zone around all stars, where planets of just the right mineral composition can develop atmospheres and life can form.