XMM-Newton is an X-ray satellite launched into Earth orbit on December 10, 1999 by the European Space Agency (ESA). XMM-Newton is actually a fully-functioning observatory, carrying three very advanced X-ray telescopes. They each contain 58 high-precision concentric mirrors, nested to offer the largest collecting area possible to catch X-rays. Unlike many other telescopes, which only make images of the objects they observe, XMM-Newton takes both images and spectra. This means it can measure the energy of the X-rays emitted by an astronomical object, which allows scientists to determine many of its physical characteristics.
XMM-Newton was initially called just "XMM", which stands for "X-ray Multi-Mirror" due to the design of the mirrors. To honor one of the world's most famous scientists, ESA attached the name of Isaac Newton to the XMM mission.
XMM-Newton can obtain spectra of far fainter objects than any previous spectroscopic X-ray mission because its mirrors have more collection area and are smoother than on any previous mission. The detectors onboard XMM-Newton are also much more sensitive, allowing fainter objects to be observed. A third advantage is that it has an unusual orbit that takes it out to nearly one third of the distance to the Moon. This highly elliptical orbit means that XMM-Newton can make long, uninterrupted observations, giving it the time it needs to see fainter astronomical objects.
Although managed and operated by the European Space Agency (see ESA's XMM-Newton outreach site), XMM-Newton has several American components:
- Columbia University Astrophysics laboratory has been working with both the software and the hardware of the Reflection Grating Spectrometer, the instrument which will give astronomers the most precise spectral information.
- University of California - Santa Barbara is in charge of the on-board software for the UV/optical monitor.
- GSFC is the coordinator of the US effort and participation in XMM-Newton. GSFC also manages the Guest Observer Facility.