Yesterday, for the first time since its complete assembly earlier this year, the 6.5-meter mirror of NASA’s James Webb Space Telescope was revealed in all its golden glory. For months, black covers have hidden each of the mirror’s 18 coffee-table-sized hexagonal segments, protecting them as engineers assembled and tested additional telescope components. Each of the segments is made of lightweight beryllium—a dull, gray, toxic metal. An atoms-thin layer of vaporized gold gives them their sunny appearance, and boosts the mirror’s reflectivity of infrared light. This will prove crucial for the telescope’s mission to observe the faint infrared glow of the universe’s first stars and galaxies when it launches in 2018.
Read more about James Webb in this recent in-depth feature.