May 26 – Launch of EXOSAT

The European X-Ray Satellite (EXOSAT) was launched on May 26th 1983, and was operational until April 9th 1986, studying x-ray binaries, active galactic nuclei, and other x-ray sources. Personally I think the best thing about it was its bizarre orbit (from 120,000 mile apogee to 300 mile perigee), but there were other highlights of the three years, including the discovery of quasi periodic oscillations in LMXRBs and x-ray pulsars. I can sense that you are just dying to know what LMXRB stands for. It’s Low Mass X Ray Binary (low mass is a little misleading, generally meaning lower in mass than the Sun).


1969Apollo 10 splashdown. Tom Stafford, John Young and Eugene Cernan were recovered by the USS Princeton, about 400 miles from American Samoa, in the Pacific Ocean. Their 8-day mission had included four orbits of the Moon, as a rehearsal for “the big one”, which was to take place later the same year.

Recovery of the Apollo 10 capsule
Recovery of the Apollo 10 capsule

1826 – Birth, in Chelsea, of Richard Christopher Carrington, recipient of the Gold Medal of the Royal Astronomical Society. His work included the demonstration of the existence of solar flares, and their influence on our planet. He now lends his name to the numbering system for sunspot cycles.


Last updated: May 10, 2019.