Mystery at Galaxy Center. Studying X-ray sources in a 130 light-year region in the center of the Milky Way Galaxy, NASA Chandra X-ray Observatory found a diffuse X-ray glow corresponding to a large, hot, gas cloud. The cloud is a mixture of 10-million-degree and 100-million-degree Celsius gas. Although escaping each 10,000 years, the gas cloud is continually regenerated and heated. Gas replenishment could be provided by winds from massive stars but the source of the heating remains a mystery. As this central cloud is the central part only of an already known X-ray emission stretching for several thousand light years along the Galaxy disk, such an extent implies that "Sgr A*", the supermassive black hole at the center of our Galaxy, is not the culprit. The magnetic field in the region nor supernova shock waves (except for the less hot part of the cloud) were not found to be responsible either. The idea that the gas cloud might be a diffuse view of not yet detected point-like sources has been ruled out too. The puzzle remains...The brightest part of the picture is where our Galaxy supermassive blackhole is lying and is about 40 light-year wide in its larger extent. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for NASA's Office of Space Science, Washington. picture courtesy NASA/CXC/UCLA/MIT/M.Muno et al.