Of all the scientific insights attained to date, one stands out boldly: Earth is neither central nor special. We inhabit no unique place in the universe. Astronomical research, especially within the past few decades, strongly suggests that we live on what seems to be an ordinary rocky planet called Earth. It is one of eight known planets orbiting an average star called the Sun. This star is near the edge of a huge collection of stars called the Milky Way Galaxy, which is one galaxy among billions of others spread throughout the observable universe.

     We all have our particular addresses; building number, flat number, street name, postal code, city, state country. It is how people can visit us and amazon can deliver your courier. But let’s expand our view for a moment. We also live somewhere within an enormously vast universe. This brings us to a question, what is our “cosmic address”?

     Are you close to an observation? It sounds like, planet, star, galaxy, galaxy group, galaxy cluster.

Let us dive in.

    We are connected to the most distant realms of space and time not only by our imaginations but also through a common cosmic heritage. Most of the chemical elements that make up our bodies (hydrogen, oxygen, carbon, and many more) were created billions of years ago in the hot centres of long-vanished stars. Their fuel supply spent, these giant stars died in huge explosions, scattering the elements created deep within their cores far and wide. Eventually, this matter collected into clouds of gas that slowly collapsed to give birth to new generations of stars. In this way, the Sun and its family of planets formed nearly 5 billion years ago.

     The Sun is located about halfway out from the center of the Milky Way Galaxy, a flattened collection of stars, gas, and dust. Our Sun is just one among several 200-400 billion stars scattered throughout our galaxy, and many of these stars are themselves surrounded by planets. The Milky Way is a member of a collection of a few dozen galaxies called the Local Group. Most galaxies in this group are much smaller than the Milky Way. Looking farther outward, the Local Group is part of a vastly larger collectionn of thousands of galaxies—a supercluster——called the Virgo Supercluster.

    We can now define our “cosmic address”—Earth, Solar System, Milky Way Galaxy, Local Group, Virgo Supercluster.

     The most massive galaxy clusters of the Laniakea Supercluster are Virgo, Hydra, Centaurus, Abell 3565, Abell 3574, Abell 3521, Fornax, Eridanus and Norma. The entire supercluster consists of approximately 300 to 500 known galaxy clusters and groups.

     Yet even this address is not complete, as the Virgo Supercluster encompasses only the local universe. The part of the universe that we can see—the observable universe— extends to 50 times the size of Virgo in every direction. Within this volume, there are about as many galaxies as there are stars in the Milky Way—several hundred billion. There are millions of superclusters in the observable universe.  The universe is not only much larger than the local universe but also contains much more than the observed planets, stars, and galaxies. Up to 95 percent of the mass of the universe is made up of matter that does not interact with light, known as dark matter, and a form of energy that permeates all of space, known as dark energy. Neither of these is well understood, and they are among the many exciting areas of research in astronomy.

     Elsewhere, other beings—perhaps with intelligence much greater than our own, may at this very moment be gazing in wonder at their own night sky. Our own Sun may be nothing more than an insignificant point of light to them—if it is visible at all. Yet if such beings exist, they must share our cosmic origin.

     Hold on with me, there are more articles to grab your attention. Coming soon…