![]() They shine brightly with the light of young stars, revealing that more stars are formed in the early universe than previously thought.Ī zoom on the HXDF. The most distant objects look very different to galaxies nearer to us, tracing how rapidly galaxies change in the early universe. Galaxies like this are very similar to galaxies we see near the Milky Way. These are the bigger objects in the picture: blue or white galaxies with sharply-focused spiral arms, or large red and orange blurs. Some of these galaxies are comparatively near by, perhaps a few hundreds of millions of light years away. This is about 45 billion light years from the Earth: light from more distant objects has not yet had time to reach us. This is the furthest point in space to which we could, in principle, see. ![]() Some galaxies in the picture lie close to the edge of the observable universe. Since that light was emitted the universe has continued to expand. The further away a galaxy is, the longer it has taken light to reach us – and the earlier in the universe we are looking. The image acts a little like a time machine. How Hubble’s astronomy looks back in time. The direction chosen was away from the millions of faint stars and dust of the plane of our own galaxy, the Milky Way. There could also be no bright sources at other wavelengths, such as X-ray or radio waves where complementary supporting observations might be made. An “empty” piece of sky was needed that contained no bright sources of visible light that might drown out fainter objects. Hubble’s key advantage is that, floating in orbit, it’s unaffected by the blurring effect of the atmosphere and so can provide images of far superior resolution than ground-based telescopes.Ĭareful planning was required for the deep field images. Observing more distant galaxies sheds light on how they form, and how their shapes and sizes change over time. The idea was not new – astronomers have always tried to take longer photographic captures that draw in more light to reveal ever more faint and distant objects. The Hubble Space Telescope began observing “deep fields” in 1995. Although only a fraction of the full moon in size, this image traces thousands of distant galaxies to the edge of the observable universe. This insignificant patch of sky in the fairly obscure constellation of Fornax is the setting for one of the most remarkable images ever captured.
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