Washington Post unveils our first observations of the atmosphere on an Earth-like planet outside the solar system:
For the first time ever, scientists are sniffing out the secrets of a “super-Earth” — the type of planet thought to be the most common in our galaxy. In a study published Tuesday in the Astrophysical Journal, a team led by scientists from University College London report on the atmosphere of exoplanet 55 Cancri e, also known as Janssen.
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Now, thanks to data from the Hubble, scientists have confirmed that this rocky hell-scape lacks water. They detected signs of hydrogen and helium in the atmosphere but no water vapor to speak of. Hints of hydrogen cyanide could indicate a carbon-rich atmosphere, according to the scientists. That would make sense, since Janssen’s mass and radius led scientists to believe it might be carbon-rich — earning it the nickname of “diamond planet.”
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Scientists can determine the makeup of a planet’s atmosphere by watching as it transits in front of its host star. The way the passing planet changes the light of the star behind it — light that’s passing through the planetary atmosphere on its way to our line of sight — can reveal what molecules are clinging to it.