The Compact Ridge is part of the vast molecular cloud within the constellation Orion. This image records the Ridge’s radio emission at a 2 centimeter wavelength, which is also characteristic of formaldehyde, the chemical used to preserve biological specimens in laboratories on Earth. That these molecules exist indicates very low temperatures inside the cloud—only a few degrees above absolute zero. 
    Here the false colors do not represent intensities of radio emission. Instead, each color indicates a velocity, analogous to the altitude contours on a topographical map.