Spiral galaxies like our own Milky Way

Four Milky-Way-like progenitor galaxies (Top-left: ZFOURGE CDFS 467; Top-right: ZFOURGE CDFS 4409; Bottom-left: ZFOURGE CDFS; Bottom-right: ZFO, URGE CDFS 6497) as seen as they would have appeared 9 billion years ago. ALMA observations of carbon monoxide (red) is superimposed on images taken with the Hubble Space Telescope. The carbon monoxide would most likely be suffused throughout the young galaxies. Credit: ALMA (ESO/NAOJ/NRAO) C. Papovich; A. Angelich (NRAO/AUI/NSF); NASA/ESA Hubble Space Telescope.