English: The European Space Agency's X-ray observatory, XMM-Newton, has imaged a spectacular set of rings which appear to expand, with a speed a thousand times faster than that of light, around the point in the sky where a powerful gamma-ray explosion took place in early December. This is the first time that such a fascinating event, called an 'echo', is seen in X-ray wavelengths. This echo forms when the powerful radiation of a gamma-ray burst, coming from far away, crosses a slab of dust in our Galaxy and scattered by it, like the beam of a lighthouse in clouds. Using the expanding rings to precisely pin-point the location of this dust, astronomers can identify places where new stars and planets are likely to form. On 3 December 2003 at 22:01 GMT the Integral satellite recorded a burst of gamma-rays in its IBIS detector (from the Imager on Board the Integral Satellite). The burst lasted for about 30 seconds and then faded. An automatic detection system (IBAS - Integral Burst Alert System) sent out a message over the internet less than 1.5 hours later. Then, about 6 hours and 10 minutes after the burst (at 4 December 2003, 04:10 GMT), the orbiting X-ray observatory XMM-Newton started observing in this direction and saw in X-rays the fading "afterglow" of the gamma-ray burst. The XMM-Newton observation lasted for just longer than 16 hours.