In AD 185, Chinese astronomers witnessed a brightness in the sky comparable to that of Mars, and this remained for eight months. This phenomena was the first recorded occurrence of a supernova explosion, but it was not until late 2006 that the remains of this cosmic event were identified. This picture, taken by the Chandra X-ray Observatory, shows an object now known as RCW 86. The image shows low-, medium-and high-energy X-rays in red, green and blue respectively. It was the study of the distribution of X-rays with energy, combined with measuring the remnant’s size, that enabled scientists to conclude that RCW 86 was created by the explosion of a massive star around 8,000 light years away

In AD 185, Chinese astronomers witnessed a brightness in the sky comparable to that of Mars, and this remained for eight months. This phenomena was
the first recorded occurrence of a supernova explosion, but it was not until late 2006 that the remains of this cosmic event were identified. This picture,
taken by the Chandra X-ray Observatory, shows an object now known as RCW 86. The image shows low-, medium-and high-energy X-rays in red, green
and blue respectively. It was the study of the distribution of X-rays with energy, combined with measuring the remnant’s size, that enabled scientists to
conclude that RCW 86 was created by the explosion of a massive star around 8,000 light years away