Astronomy Picture of the Day . On the Trail of 2008 TC3 . 8.11.2008 . ... In this colorful mosaic, filaments of gas and dust span some 9 degrees across central Cygnus, a nebula rich constellation along the northern Milky Way. ... The picture was made using a prototype instrument known as MAD (Multi-conjugate Adaptive optics Demonstrator) mounted on one of the European Southern Observatory's 8-meter diameter Very Large Telescope units in Chile. Seventeen Hundred Kilometers Above Enceladus . ...