Pinned
Cosmic colors at sunrise; never get tired of seeing what the new day brings
Don Pettit
1,062 posts
Don Pettit
@astro_Pettit
NASA Astronaut. Photographer. Scientist. Inventor.
Joined June 2011
- In microgravity, crystals experience "hopper growth," where the outer edges and corners grow at faster rates than the flat faces, creating a step-like appearance. This timelapse records their growth inside a thin water film. Look closely, and you will see the patterns emerge!
00:00 - Sunbeams viewed from Earth and space above East Africa, in collaboration with National Geographic's @BabakTafreshi. Crepuscular rays are one of the day-night cycle's many beautiful phenomena!
- Denver, Colorado as seen from the ISS. The Denver airport, one of the largest in the world, is the dark patch right of center. To the west, city lights are abruptly extinguished by the Rocky Mountains.
- Aurora watching into an orbital dawn. This never gets old!
00:00 - Installing a semiconductor furnace on ISS! The furnace will first melt and then solidify semiconductor materials without interference from gravity induced convection. Crystal research has been performed in space for decades, with this experiment using gallium arsenide.
- Sun glint off the Euphrates river centered on Ash Shamah, Iraq where specular reflections off the water give it a polished silver sheen.
- Cloudy plateaus over the Western Sahara, eroded by the desert into a stark topography observable from orbit.
- In weightlessness, water can take forms that are not possible under normal gravitational conditions. One example being thin sheets, 500 microns thick, formed in a wire loop like in a soap film but here as pure water with no surfactant.
00:00 - Red atmospheric airglow, excited by solar activity, illuminates the rim of our planet. Viewed from above and below, on the ISS and Maui island, in collaboration with National Geographic's @BabakTafreshi
