Apertura 10" f/4 Imaging Newtonian OTA - 10F4N - Telescopes at Telescopes
150/750 Newton reflector Complete set of self-made telescope accessories | eBay
NASA History - The Newton X-ray Multi-Mirror (XMM) telescope was launched #OTD on this day (December 10) in 1999. The telescope was built by the European Space Agency (ESA) as a complement