Chandra X-ray & VLA Radio Composite image of G1.9+0.3 This composite image of the supernova remnant G1.9+0.3 combines the Chandra X-ray Observatory image taken in 2007 (orange) with the Very Large Array radio image taken in 1985 (blue) and 2008 (yellow). The difference in size between the images gives clear evidence for expansion, allowing the age of the remnant and the time since the original supernova explosion (about 140 years) to be estimated. (Credit: X-ray (NASA/CXC/NCSU/S.Reynolds et al.); Radio (NSF/NRAO/VLA/Cambridge/D.Green et al.))