G1.9+0.3 supernova

Scientists have discovered what they believe to be the youngest known supernova, or exploding star, by tracking its size using NASA's Chandra X-ray Observatory and the National Radio Astronomy Observatory's Very Large Array.

When originally tracked in 1985 (left) using the Very Large Array, supernova remnant G1.9+0.3 was thought to be between 400 and 1,000 years old, but newer measurements by the Chandra X-ray Observatory (right) show surprising growth and indicate that it is a mere 140 years old.

May 15, 2008 1:14 PM PDT

Photo by: X-ray (NASA/CXC/NCSU/S. Reynolds et al.); Radio (NSF/NRAO/VLA/Cambridge/D. Green et al.); Infrared (2MASS/UMass/IPAC-Caltech/NASA/NSF/CfA/E. Bressert)