Backlit wisps along the Horsehead Nebula's upper ridge are being illuminated by Sigma Orionis. Original from NASA. Digitally… https://www.rawpixel.com/image/418636/horsehead-nebulas-upper-ridgeFree Image from public domain licenseImage of a nebula taken using a NASA telescope - Original from NASA. Digitally enhanced by rawpixel. https://www.rawpixel.com/image/441249/free-photo-image-hubble-flame-galaxyFree Image from public domain licenseImage of a nebula taken using a NASA telescope - Original from NASA. Digitally enhanced by rawpixel. https://www.rawpixel.com/image/440597/free-photo-image-galaxy-green-universeFree Image from public domain license