Mother Earth is a great artist: Look no further than auroras—natural light displays that paint the sky with stunning colors. The product of violent collisions
between Earth’s atmosphere and particles from the Sun,
Twin rockets were released some 71 to 155 miles into the ionosphere on Friday to measure atmospheric density and temperature. They also deployed visible tracers—trimethyl aluminum (TMA) and a barium/strontium mixture—that create colorful clouds, allowing astronomers to track the flow of neutral and charged particles, respectively.