How do we know what we do?

Do you ever wonder how we are able to know what we do about these objects that are such large distances from us to the point where light takes thousands of years just to travel from these objects to us. Well when visible light can no longer be used to study these objects we use what is called far-infrared which works off the fact that thermal radiation of interstellar dust contained in molecular clouds will begin to glow when infrared light is shined on them. This means that they can be detected long before the visible light ever makes it to the earth from these distant objects and allows us to continue studying objects at the deepest parts of the universe. Just think of how far these distances are. It is truly a remarkable feat.