Thursday, January 27, 2011

Stare into the distance and see the past; new galaxy discovered

How far away can the human eye reach? How far away can we see with the help of technology? And can we see back in time and into the future? Our universe is packed with objects that are emitting energy, radiation, in various wavelengths. Radiation is also released at cosmic events. The most famous  cosmic event is the big bang, the theory that everything in this universe originated from one small singular point that then expanded. There is an echo of radiation in space from this event that scientists can analyze. With the help of technology, not only can our minds pierce into the depths of space, we can also look back in time. 
Humans have always studied the lightbodies above us, mirroring ourselves in starconstellations and giving them power over our destinies. We always wanted to look even further, building various solutions as telescopes. The Mama of all telescopes is called Hubble. It recently took a photo of a galaxy that lies 13.2 billion light years away. (They gave it an extremely unsexy and boring name, seriously!) This is not only a measure of distance, but a measure of historic events. The term lightyears is the distance that light travels during a year. We are looking into the past.
Because the object's light took this long to reach Earth, it takes us back to when the universe was approximately 480 million years old. In universal time, that is childhood. The new find reveals that galaxies were forming and growing quite fast at this very early time in the universe.
How do did the astronomers analyze the light? In this case the light has travelled so long that it has so called “redshitfed”, the light waves have been stretched. In order to estimate the nature of the light and appreciate the distance to the galaxy the scientist needed to look through different filters..
The question is of course, if technology strech the limits evenmore, will we see more galaxies even more remotely located or not? Will we look back into a time where the universe was a mere toddler. Was the emergence of galaxies a very early event? The hubble successor will show us. 
What can we learn from looking into the stars and back through the light years in this way?
The co-author Marijn Franx of Leiden Observatory stresses, “if looking back to a cosmic age of 500 million years reveals just one candidate galaxy in the Hubble image, and if even that one turns out to be something else, it really means galaxies were extremely rare during that early epoch. "In fact," says Franx, "it would only strengthen our conclusion that we're looking back to a time when the very first galaxies were assembled."
No matter what the new telescope will show us, we can all look back in time. We just have to catch a glimpse of a star. The night sky is a glittering echo of ancient events, swirling over our heads the history of this universe are shedding lights on our paths.


From the article by Bouwen et al for the photographer nerds “The new Hubble Ultra Deep Field (UDF) image was obtained by combining near-infrared pictures made by the Wide Field Camera 3 (installed in May 2009) and optical photos made by Hubble's older Advanced Camera for Surveys. "With 40% more sensitivity compared to earlier exposures, we were able to push to fainter and more distant sources,"

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