From Galactic Dust To The Big Bang

Will you look at the dust in this galaxy! Thrilled astronomers are checking out a new picture of the entire sky viewed in a whole new light. The stunning image, built up by a European space telescope, reveals vast swathes of dust filling our home galaxy, the Milky Way. 

Planck’s microwave image of the sky

They stretch out across every part of the heavens like great bluish-white tendrils in the first picture of the entire sky from the Planck satellite, launched last year.

Experts are calling the image an extraordinary treasure chest of new data that will keep astronomers busy for years to come. For apart from the dust, it also red regions of hot gas in our galaxy.

And a bonus is the mottled yellow patches that dot the sky. They are the echo of the Big Bang that created the universe nearly 14 billion years ago – an ancient relic known as the Cosmic Wave Background which has previously been measured from the Earth.

The bright line running across the centre of the image is the Milky Way – our spiral galaxy seen from within. It is 100,000 light-years wide and contains 100 billion stars. The amount of dust in the galaxy comes as no surprise because it is from such dust and gas that stars and planets are known to form.

Planck’s picture of the sky looks different to our usual view because it is observing microwave radiation rather than visible light. The technique will provide new information to add to the jigsaw of knowledge about how the universe formed.

Launched by the European Space Agency with another telescope called Herschel, Planck began it observations last August. It is due to map the entire sky three more times before the end of its mission in 2012. Planck Survey Scientist Professor George Efstathiou, of Cambridge University, said “Planck is working brilliantly and we expect to learn a lot about the Big Bang and the creation of our Universe.”

Dr David Parker, Director of Space Science and Exploration for the UK Space Agency, said: “Planck has ‘painted’ us its first spectacular picture of the Universe. This single image captures both our own cosmic backyard – the Milky Way galaxy that we live in – but also the subtle imprint of the Big Bang from which the whole Universe emerged.”

Dr David Clements, of Imperial College London, said: “Just looking at the pictures you can tell we’re seeing new things about the structure of our galaxy. Once we’ve done that, and stripped away these foregrounds, then it’s on to the Cosmic Microwave Background and the glow of the Big Bang itself!”

Incidentally, I have been asked what the black bit is! The entire sky is shown within the oval shape – similar to the way the whole Earth is sometimes displayed on a map – and the black edging is like a photo frame, not part of Planck’s universe.

• Discover space for yourself and do fun science with a telescope. Here is Skymania’s advice on how to choose a telescope. We also have a guide to the different types of telescope available. Check out our monthly sky guide too!

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