Dark Nebula Dark nebulae are so dense that they are opaque
{"Image DocumentName": "Dark Nebula Dark nebulae are so dense that they are opaque", "Image ImageDescription": "They appear as dark blobs against a background of distant stars.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}