New article on Inoreader

https://www.youtube.com/channel/UCKv3UT62zZgBWeZ4j8gpkjgHow the Universe Works - National Geographic The Universe - Space Discovery Documentary -

And when we find life, how will we know? The answer has a lot to do with rainbows. As Isaac Newton recognized, white light shot through a prism (or through curtains of mist seen with the sun at your back) is exposed for what it really is: a band of color spanning violet to red, characterized by “wavelength.” Chemicals and gases in the atmospheres of planets can absorb certain slices of this band, called a spectrum, and leave behind a narrow black gap.

When we analyze light shot by a star through the atmosphere of a distant planet—a technique known as spectroscopy—the effect looks like a bar code. The slices missing from the light spectrum tell us which constituents are present in the alien atmosphere.