NASA: Midmorning sun seen in Greenland by our @NASA_Ice Bridge mission as it surveys polar ice: https://t.co/7ajOoZtTSO https://t.co/tVUQkZeT6w - 2016-09-16 17:34:01

NASA: A lone star shines brightly from deep space in this image captured by @NASA_Hubble. Details: https://t.co/Y4Fy3VsTyl https://t.co/T4k2HdL3Jm - 2016-09-16 16:08:02

NASA: We're harnessing the power of space to fight cancer, w/ @Space_Station & @NASAJPL research: https://t.co/220CakW3nU https://t.co/PNinV5o0F6 - 2016-09-16 21:18:02

NASA: Space & cancer research both face challenges of finding meaning in data. We've teamed up: https://t.co/LdANpe8Z4M https://t.co/j8TbasIaPz - 2016-09-16 20:15:31

NASA: In space, @NASA_Astronauts Kate Rubins discusses cancer research on @Space_Station. Watch: https://t.co/KX5g7yYnYG https://t.co/TGN6TY1q1P - 2016-09-16 19:55:02

NASA: 2 yrs ago, we selected @Commercial_Crew partners to take astronauts to @Space_Station. Info: https://t.co/MIvFaXOLj9 https://t.co/HOSpLoaVZA - 2016-09-16 22:14:03

NASA_Hubble: PGC83677 is a lenticular galaxy- the median on the spectrum of elliptical & spiral galaxies. https://t.co/WA1RWG43gE https://t.co/rJItdh0QNJ - 2016-09-16 14:04:01

NASA: Explore the Asteroid Redirect Mission & preparations for next @Space_Station crew launch on This Week @ NASA. Watch: https://t.co/2P1yEqMfxQ - 2016-09-16 23:29:02

CERN: Don't miss today's #GravitationalWaves webcast https://t.co/8qQzqjCgx7 See also https://t.co/yze3mvvIgq Image @LIGO https://t.co/ePM5UcaDVm - 2016-09-16 15:47:33

NOAASatellites: On 9/10, Arctic sea ice extent shrank to 4.14 mil. square km- Tied for 2nd lowest on record https://t.co/RPJ2k9FvBW https://t.co/0OCUecaT89 - 2016-09-16 17:00:37