111K views · 2.1K reactions | Evidence of helium was first observed on this day in 1868 by French astronomer Pierre Janssen during a total solar eclipse. ☀️ Take a look at helium atoms forming in this amazing cloud chamber, as Christmas Lecturer Peter Wothers demonstrates. | Royal Institution of Great Britain | Facebook

37K views · 1.6K reactions | Don’t lose your chill, but helium is the coolest element. (It's got the lowest boiling point!) Apply pressure, and it gets even cooler. Find out how pressurized helium helps keep the cryocooler of Webb’s MIRI instrument only about 7 Kelvin (-448 degrees F, or -266 degrees C) in the latest episode of Elements of Webb. ❄️ Credit: NASA's Goddard Space Flight Center | NASA's James Webb Space Telescope | Facebook