XMM-Newton telescope. Artwork of the XMM (X-ray Multi-Mirror)-Newton X-ray telescope in orbit above the Earth. This European Space Agency (ESA) satellite has three separate X-ray telescopes (large openings) which allow study of high-energy phenomena such as supernovae and black holes. Each of the X-ray telescopes contains 58 concentric mirrors, positioned so as to glance X-rays onto the detectors at the telescope's rear (upper right). The telescope has a highly elliptical orbit around Earth, reaching 114,000 kilometres away at its furthest point. This allows it to observe from above Earth's large radiation belts. XMM-Newton was launched on 10th December 1999.