MYSTERIES OF OUR UNIVERSE.

Telescopes Are Time Machines.....

The farther we look out into space, the farther we are also looking back in time. As hinted earlier, telescopes are a type of time machine. It is an ingenious machine to see the unravelling mysteries of our universe. As we all know that NASA uses the term GREAT OBSERVATORIES to refer specifically to four space telescopes named after famous scientists:Hubble, Compton, Chandra, and Spitzer. soon they will add a fifth satellite, the WILKINSON MICROWAVE ANISOTROPY PROBE(WMAP), to this impressive list of NASA accomplishments. Once HUBBLE captured an image of a galaxy 400 million light years away. This means light from these galaxies takes 400 million light years to travel Earth. We do not see the galaxies as they are today, we seem them as they were 400 million light years ago in the throes of a cataclysmic collision. Now, all the excitement is probably over there, maybe that galaxy and one of its neighbouring galaxies merged and now they are one big happy galaxy. TELESCOPES SHOW US THE PAST AS IT IS ACTUALLY HAPPENING. It is a tremendous boon to science. Well,  I am also largely fascinated by the skies in the night as i always wonder how old the stars might be and how many light years it would have taken for the light to travel here.....it's really amusing and amazing to know all these wonders happening in our universe! It's indeed a spectacular phenomenon. Astronomers can therefore,  look farther back through time by studying progressively more distant objects.

The chief difficulty in employing this "time machine" to observe the cosmos during its past epochs arises from the fact that distant objects appear fainter than closer ones. We must therefore,  capture and analyze the light from progressively dimmer objects as we push farther back into the past. Specialized instruments are needed to study our nearest neighbor, the Andromeda Galaxy, which is 2 million light-years away. But this companion of the Milky Way shines a million times more brightly than a similar galaxy seen at a distance of 2 billion light-years! This comparison gives a sense of how difficult it will be to obtain images of objects formed close to the Big Bang era more than 10 billion years ago. During the past few years, the Hubble Space Telescope has obtained long-exposure images that reveal the faintest objects ever detected. Some of these objects are galaxies seen during their early developmental stages when they were rich in young, hot, and very luminous stars. To peer still farther back through time, to reach the era when stars first began to shine, astronomers need a telescope that can detect extremely low intensities of infrared light. Astronomers need sensitivity in the infrared part of the spectrum because the light from these young stars in distant galaxies, even though emitted as visible light, has been stretched by the expansion of the universe to appear to us as infrared light. The Hubble Space Telescope can observe the shortest-wavelength portion of the infrared domain, but its 2.4-meter mirror is too warm and too small to detect the faint glow from the most distant young galaxies. To observe galaxies in their earliest epochs, the survey report recommends a new, advanced- technology telescope designed to work best in the infrared part of the spectrum. In an orbit a million miles from Earth, this telescope will become so cold that its own infrared glow will be insignificant compared with the light from the distant galaxies, something an earthbound telescope could never achieve. Also, being above Earth's veil of air allows us to see radiation that cannot penetrate it, and guarantees the sharpest images the telescope can deliver, free from the turbulence in Earth's atmosphere that handicaps telescopes on the ground.Well dont get upset we all earthlings and humans like you and me in whose blood runs love for cosmology and astronomy, no one can stop us from exploring, as i always say exploring should never stop neither your quest for the answers and mysteries of our intriguing universe.

"THE NIGHT SKY IS A TIME MACHINE. LOOK OUT AND YOU LOOK BACK IN TIME. BUT THIS TIME TRAVEL BY EYESIGHT IS NOT JUST THE PROVINCE OF ASTRONOMY. ITS AS CLOSE AS THE MACHINE ON WHICH YOU ARE READING THESE WORDS. YOUR PRESENT EXISTS AT THE MERCY OF MANY OVERLAPPING PASTS. SO WHERE, THEN, IS "NOW"?.........  

ITS DEEP INDEED, TRY TO UNDERSTAND THE LAST 5 LINES!!! AND DONT FORGET ON THIS SATURDAY MERCURY WILL BE SEEN FOR THE FIRST TIME IN 10 YEARS, SO YOU WILL WANT TO DEFINITELY TAKE OUT YOUR TELESCOPES.!! HAPPY EXPLORING!!......(6th MAY-SATURDAY).