• A repeated analysis of the exoplanet’s atmosphere suggests an abundance of a molecule that on Earth has only one known source: living organisms such as marine algae.

  Have you ever wondered how astronomers learn what’s in a faraway planet’s atmosphere? Here’s your one-sentence answer: Gases appear as different colors through the various colors of light in a prism; that is, each gas in a planet’s atmosphere blocks specific colors of starlight. Here’s your more detailed explanation that I learned from watching a couple of episodes of the rebooted Cosmos.
  Each gas absorbs very specific wavelengths of light, like taking tiny, precise “bites” out of the spectrum.

  For example, if you pass sunlight through a prism, you see all the colors of the rainbow smoothly changing from red to violet. But if that same light passes through a gas first, the gas will absorb very specific wavelengths, causing thin dark lines to appear in certain spots of the rainbow spectrum.

  These absorption lines are like fingerprints – hydrogen absorbs different specific wavelengths than oxygen, which absorbs different wavelengths than carbon dioxide, and so on. Each gas has its own unique pattern of these dark lines.

  So when astronomers look at starlight that has passed through a planet’s atmosphere, they don’t just see “the color blue” and think “that must be water.” Instead, they see specific patterns of these thin dark lines in the spectrum and can match these patterns to known gases.

  She briefly explains it here and has some other fun info on the subject to share.

On paper, Salvador Cavazos earns less than $300,000 to run Valere Public Schools, a small Texas charter network. But taxpayers likely aren’t aware that his total pay makes him one of the country’s highest-earning superintendents.