Explanation: In 1787, astronomer William Herschel discovered the NGC 2392 . From the ground, NGC 2392 resembles a person's head surrounded by a parka hood. In 2000, the Hubble Space Telescope imaged NGC 2392 in visible light, while the nebula was imaged in X-rays by the Chandra X-ray Observatory in 2007. The above combined visible-X ray image , with X-rays emitted by central hot gas and shown in pink, was released last week. From space, the nebula displays gas clouds so complex they are not fully understood . NGC 2392 is clearly a planetary nebula , and the gas seen above composed the outer layers of a Sun -like star only 10,000 years ago. The inner filaments visible above are being ejected by strong wind of particles from the central star. The outer disk contains unusual light-year long orange filaments. NGC 2392 Nebula spans about 1/3 of a light year and lies in our Milky Way Galaxy , about 3,000 light years distant, toward the constellation of the Twins ( Gemini ).