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Credit: NTT/ SUSI DEEP FIELD

Keen to keep pace with the Hubble Space Telescope, astronomers at the European Southern Observatory (ESO) have produced their own ground-based colour image of far-distant objects (right) which ESO describes as being “unique in covering four bands with an image quality better than one arc-second”.

The image, produced by the SUperb Seeing Imager (SUSI) Deep Field project of the 3.5-metre New Technology Telescope (NTT) at La Silla, Chile, involves 122 frames in four colours — blue, green-yellow, red and near-infrared — of an area of ‘empty sky’ just south of the celestial equator.

ESO admits that a shorter exposure time and brighter sky background, caused by light emission in the upper atmosphere, mean that the image is not as deep as that produced by Hubble. But its high quality is said to justify the construction of the Very Large Telescope (VLT) in Chile, which is due to start operation within a few months, and one of whose goals will be to perform spectroscopic analysis of distant galaxies.