Space telescope reveals spectacular Universe images
Updated on 06 July 2010
As a telescope sends back extraordinary pictures of the Universe - Professor Ofer Lahav and top theologian Dr Andrew Pinsent tell Channel 4 News how it could unlock many scientific and religious secrets.
The images are the first "all sky" pictures from the Planck telescope, launched last year by the European Space Agency. Its aim was to photograph the oldest light in the cosmos, and answer questions on the Universe's past, present and future. The image also provides new insight into the way stars and galaxies form.
"This is the moment that Planck was conceived for," said ESA Director of Science and Robotic Exploration, David Southwood.
"We're not giving the answer. We are opening the door to an Eldorado where scientists can seek the nuggets that will lead to deeper understanding of how our Universe came to be and how it works now. The image itself and its remarkable quality is a tribute to the engineers who built and have operated Planck. Now the scientific harvest must begin."
What does the image show?
The all-sky image incorporates the closest portions of our own Galaxy, the Milky Way, and stretches out to the furthest reaches of space and time.
The bright line across the centre of the image is our Galaxy. Surrounding it are streamers of dust – a so-called galactic web – where new stars are being formed.
For scientists, however, it is the edges of the image that could prove to be the most exciting.
Professor Ofer Lahav, vice president of the Royal Astronomical Society and astronomy chair at University College London, told Channel 4 News the telescope could also help provide answers to another key question: what is the Universe made of?
"The stuff we are made of – you and me, the trees around me – is only 4% of the total 'cosmic budget' or 'cosmic cake,'" he says.
"We think 21% or so is due to cold dark matter. And 75% is the even more esoteric dark energy.
"It’s a bizarre and very interesting phase of cosmology because 96% of the Universe is unexplained."
Read more from Professor Lahav
The beginning of the Universe
The motted red backdrop represents "cosmic microwave background radiation" – the oldest light in the Universe and the remains of the fireball "Big Bang" from which the Universe was born 13.7 billion years ago.
The image of the Milky Way shows us what our Universe, or the local bit at least, looks like now. The edges of the image show us what the Universe looked like when it began, and the Planck scientists believe it is these parts of the photograph that could hold the answers to the question of how this happened.
The different colours in the image represent minute differences in temperature and density of matter across the sky. Such irregularities, in some cases, evolved into the denser regions that have become today’s galaxies, like our own.
This background radiation covers the entire sky, but is blocked in the image by the Milky Way's emission, which scientists plan to digitally remove in order to view the background properly.
They want to find out whether the image will then reveal the cosmic signature of the period called "inflation". This period theoretically took place just after the Big Bang and resulted in the massive, incredibly fast expansion of the Universe.
Planck will continue to map the Universe, and by the end of its mission in 2012 it will have four all-sky scans and the most precise picture ever of the Universe.
Or, as Jan Tauber, ESA's Planck project scientist explained: "This image is just a glimpse of what Planck will ultimately see."
And while for scientists these images are a joy to behold, for some religious people they can raise very profound questions about the role of a god or gods in creating the Universe.
However, Dr Andrew Pinsent, an Oxford University theologian who formerly worked as a particle physicist at CERN, and who will tomorrow host a conference called 'God and Physics' at the university, told Channel 4 News that science and religion are inextricably linked, rather than opposed.
"Most people today are unaware that it was a priest, Fr Georges Lemaitre, who first developed what is today called the "Big Bang" theory, over thirty years before the discovery of the microwave radiation mapped by these extraordinary pictures," he said.
"For many religious believers, these pictures obviously resonate with the opening words of Genesis, "Let there be light!" and may, I think, re-kindle a healthy sense of wonder at the majesty of the cosmos."
Jan Tauber, project scientists for the Planck mission at the European Space Agency, explains the photographs to Channel 4 News.
How are the pictures taken?
You can think of Planck as a camera pointed at the sky (though the pixels in this camera are widely spaced). The camera's field-of-view is swept repeatedly and slowly across the sky by the satellite and traces a large ring. A "snapshot" of the sky is taken by the camera at very short intervals - every few milliseconds. All these snapshots can be put together by software into an image of the complete ring. As the satellite moves around the Sun, the ring sweeps slowly over the whole sky. After 6 months, the ring has covered about 95 per cent of the whole sky. All the ring images can then be put together by software into a single image of the whole sky.
What is the most important thing you are hoping the Planck mission will discover?
There are many things we hope to do with the Planck data. To single out one important thing: many scientists hope that Planck will detect a very faint signal (called "B-modes") which should have been generated by inflation (a period of very rapid expansion theorised to have led to the birth of the Universe). If it is detected, it would give very strong support to the idea that inflation actually took place.
Can you explain the shape of the picture – is that the shape of the Universe?
And what is the black background?
When we want to visualise the whole sky, we have to select a "projection". It is the same problem as making a map of the spherical Earth - it can be done in different ways which emphasize different aspects. The "egg" shape is a specific projection system called Mollweide which is preferred by astronomers. But we could just as well show a rectangular image (we don't like to do that as it distorts the regions near the poles - same problem with Earth maps). So there is no particular significance to the egg-shape, nor to the black background... and has nothing to do with the shape of the Universe ! If you look at the end of the animation we provided, it shows nicely how the spherical sky is "opened" into the flat Mollweide projection that we use for the images.
