While answering a question in the backdrop of his conflict with the Catholic Church, Galileo once remarked, "Bible teaches how to go to heaven, not how the heavens go." Now, 400 years after Galileo attempted to know the heavens using his 'spy glasses', our machines can narrate the story of the heavens in much more detail.
Among them is the world's most famous telescope, Hubble Space Telescope, which turned 21 on April 24, 2011. During the last two decades of operation, it saw the birth and death of stars and captured many turbulent cosmic collisions. It granted us an exotic vision to enjoy the wonders that lie underneath the tempestuous cosmic ocean. Some called it 'The Mirror on the Universe' while others described it as 'The Eye on the Sky'. It continues to beam hundreds of images back to earth every week.
Named after the American Astronomer Edwin Hubble, whose observations in the 1920's supported the theory of expanding universe, Hubble has been in continuous action for the last two decades. Since the launch in 1990, most of its original instruments have been upgraded or replaced by service missions. Hubble, located at about 565km above the earth's surface with an approximate size of a school bus, completes one full orbit around the earth in 97 minutes.
In addition to many startling discoveries, the Hubble images became the art work of the cosmos. The Hubble Ultra Deep Field (HUDF), completed in 2004, is an image of a small region of space created using Hubble data accumulated over a period of four months. In fact, some of these objects date back to the baby universe, approximately 13 billion years ago, when the galaxies were just forming from the seeds of Big Bang. This particular image contains an estimated 10,000 galaxies in different shapes and sizes. Each of them might contain billions of stars and many possible planetary systems. Scientists were perplexed at the mere existence of such large number of galaxies, and some even dubbed it as "Kingdoms of Heaven."
The mystery surrounding the creation and existence of the universe reaches out to us in the form of light energy. Hubble has done more than any other modern telescope to garner that energy, and to carve the history of the universe for the coming generations. Edwin Hubble observed and measured the departure of galaxies using a technique known as the redshift in physics. Now we know that the galaxies not only depart from each other but their exodus is accelerated by the inexplicable dark energy.
If our current notion of the universe is true, in the far future, our own Milky Way galaxy will be left alone in the galactic playground with other galaxies have receded to the unknown parts of the cosmos. The finite speed of light will not overcome the unlimited space that would be created among the galaxies due to the accelerating nature of their retreat. This could lead our future generations to assume that their galaxy is same as the universe. If preserved, the Hubble images will enlighten our descendants with the chronicle of that ultimate isolation!