People live their lives, never realizing the enormous world they live in. We are so busy in our every day life, that we never think about bigger picture and The Sky above us. For most people, when they look up they just see blue sky and that's it. But the reality is that there is so much beyond the sky, that our brain can't even imagine it fully. Our earth, us and everything on this planet is so small compared to the universe out there. Before we can truly grasp the gravity of the threats as well as the beauty that surrounds our planet, we must first realize just how small our Earth is. The circumference of Earth at the equator is about twenty four thousand eight hundred and seventy four miles and from the North pole to the South pole it's about twenty four thousand eight hundred and sixty miles. Within our Solar System we are the fourth largest planet. After us, we are dwarfed by Neptune, Saturn, Jupiter and our own star which is 93 million miles away from us-The Sun. Our Sun is a pretty big star. It is 1,392,000 Km in diameter, which makes it 109 times wider than Earth, but it's nowhere near the sizes of other stars that we know about. To name just a few larger stars for perspective, there is Eta Carinae, a star is over five million times larger than our Sun. There is also this Sun, named Betelgeuse. Calculations of its mass range from slightly under ten to a little over twenty times larger than our Sun. There are much more stars like that. If you put Betelgeuse in our Solar System, it would destroy our planet in a matter of seconds.
We are part of a Milky Way Galaxy. There are trillions of stars in our galaxy and nearly all of them are circled by at least one planet. Also within our Milky Way Galaxy we are not the only Solar System. So far astronomers have found more than five hundred Solar Systems and discovering new ones every year. Scientists estimate that there may be tens of billions of Solar Systems in our Galaxy alone. So can you imagine how many Solar Systems are in the whole Universe? I bet, you can't. Travelling out 150,000 light-years you can see just how small even the biggest stars are within our Galaxy.
It takes our Sun 200 million years to complete an orbit of the Milky Way. That's how big our own Galaxy alone is. 2.5 million years away is Andromeda Galaxy. It is a neighbor of our Milky Way. Andromeda and Milky way will collide with each other in a few billion years from now and using the Hubble Deep Field known as HDF, we can see a very small series of space and observations by the HDF telescope itself. It shows hundreds of Galaxies. 5 billion light-years out of our Milky Way is the cosmic web where billions and billions of Galaxies are estimated to reside and finally 200 billion light-years out is a cosmic microwave background radiation. Afterglow is what we believe that started us. It is the only thing estimated to be left from Big Bang. That's how big and maybe infinite our Universe is, but what is beyond this? Other Universes or immeasurable Heavens. We have only discovered less than 0.1% of Universe and we are yet to find a life on other planets or galaxies. The Universe is so big, is it possible that our small Earth is the only place where the Life thrives or are we in fact not that alone? I think either thought is terrifying. For now, all we know is that all in justices, political and religious existence theories or all loves, sorrows, hopes and dreams, extinct species like the dinosaurs and species yet to come...all pasts, presents, futures, thoughts and actions only exist on our small and insignificant planet alone. On This sort of scale you truly start to think about what really matters to you, what doesn't matter anymore and what never did. What do you think? Are we alone?
Source: Wikipedia and Google. Different books about Universe.
