If you explore the night sky it won’t be long before you realize there is a lot of dust and gas up there. The interstellar dust between the stars accounts for 1% of the mass of the interstellar medium but reflects 30% of the starlight in infrared wavelengths. The dust plays a key role in the formation of stars and the evolution of the galaxy. A team of astronomers has attempted to map the dust out to a distance of 3,000 light years and have just released the first 3D map of the dust in our galaxy.