24 October 2010
There is a paper in NATURE this week that has caught the attention of a lot of people. Even those who are not into astrophysics!
Awhile back the Hubble telescope took the image you see below. See that little smudge?
Astronomer Matt Lehnert from the Observatoire de Paris and a team of scientists decided to use the new Very Large Array(VLT) telescope in Chile to see of they could capture enough light from that smudge to measure the red shift.
Remember that the farther an object is away from Earth the faster it is moving away from us. The entire universe is expanding.
Think of all the galaxies we can see including our own on the skin of a balloon that is slowly being blown up. They are all getting further apart. The farther away an object is the faster it is moving away from us.
Astronomers can measure the shift in the frequency of light to see how fast an object is receding from us. They can then use this to estimate the distance it is from us.
Matt Lehnert and his team were able to do it and were stunned to see a redshift of 8.6. That means that little smudge is 13.1 billion light years away! That means of course that we are seeing the galaxy as it was 13.1 billion years ago. The Earth itself is only 4,500 million years old!
Think about that. You are seeing something as it was 13 billion years ago. You are literally looking back in time.
The universe was only about 600 million years old then. This is just after what is called the dark ages. The universe was not visible after the big bang until it had cooled enough for photons to from and travel.
Marcel Alvarez is a Canadian astrophysicist and he has a great poster that explains the very wild early universe! Click the image to get the BIG picture.