Sunday, October 24, 2010

Newsy: Scientists Discover a Galaxy Far, Far Away

Astronomers have identified a galaxy that's the oldest, farthest object discovered by humans.

Astronomers working with the European Southern Observatory, have discovered the oldest, most distant object ever detected by humans: a galaxy 13.1 billion light years away. Scientists say they’re seeing this galaxy as it was just 600 million years after the Big Bang, meaning if the universe were a 40-year-old human, this galaxy is the finger painting it made at 19 months old. (Video from European Southern Observatory)

Engineer Paul Czysz tells TechNewsWorld that this galaxy... “ about the first object that you can see, period. This had to be very shortly after the suns got enough density that they could ignite.”

Experts explain, since the observed light came from 13.1 billion light years away, they’re basically looking back in time at this galaxy 13.1 billion years ago. Study co-author Malcolm Bremer explains what probably happened to this ancient galaxy after it emitted the light we’re seeing now: “It’s likely that a galaxy like our own, the Milky Way, is built up from building blocks that are very much smaller than the Milky Way is today, made up of multiple components. And perhaps one of the earliest components of galaxies like the Milky Way is an object like the one that we’ve been observing.”

The difficulty in finding galaxies this distant is partly that their light is very dim and very redshifted -- or stretched -- and partly because the universe was filled with hydrogen gas this early in its life. That gas had a good chance of absorbing the galaxy’s light so it couldn’t be detected today, like an opaque fog. The European Southern Observatory’s Dr. Joe Liske explains why being able to find a galaxy like this, in spite of the difficulties, is good news: “So, holding the record for having measured the red shift of the most distant object in the universe is not just a trophy to hang on the wall. It does have important astrophysical implications. This is the first time that we’ve managed to obtain spectroscopic observations of a galaxy from the era of re-ionization, in other words, from the time when universe was still clearing out the hydrogen fog.”

So this galaxy isn’t just the oldest and most distant object detected, but it’s very nearly the oldest and most distant object scientists CAN detect. Light from this galaxy just now getting to Earth has been travelling through space almost as long as there has been space. New equipment, like the James Webb Space Telescope scheduled for launch in 2014, will be able to detect that light in greater detail. Astronomer Phil Plait looks forward to what the new technology will teach us: “Our understanding of the infant Universe will explode. Even more fun will be all the weird things we’ll see that at first we won’t understand. How can a galaxy like this have formed so rapidly after the Big Bang? Did the stars form first, or later, or did it all happen at the same time? ... What other types of objects are out there ... that we haven’t seen yet?”

Writer: Steven Sparkman

No copyright infringement intended. For educational, non-commercial purposes only.

No comments:

Post a Comment

English Tests, Exams and Deadlines

Find us here

CBBC Newsround | Home