Complex sentence: The pictures from Luna 9 were not released immediately by the Soviet authorities, but scientists at Jodrell Bank Observatory in England, which was monitoring the craft, noticed that the signal format used was identical to the internationally agreed Radiofax system used by newspapers for transmitting pictures.
Split into simpler sentences: The pictures from Luna 9 were not released immediately by the Soviet authorities. Instead, the Jodrell Bank Observatory in England, which was monitoring the craft, noticed that the signal format used was identical to the internationally agreed Radiofax system used by newspapers for transmitting pictures.