How much mass do flocculent spirals hide? The featured true color image of flocculent spiral galaxy NGC 4414 was taken with the Hubble Space Telescope to help answer this question. […]

Quite a week! Take a look back at our week in images with @Thom_astro & #Galileo launches https://t.co/npOr2kNyfg pic.twitter.com/BSLmrLraFq — ESA (@esa) November 20, 2016

Call for media: Talk to @Thom_astro aboard @Space_Station about his #Principia mission https://t.co/Rz7foxjr3V pic.twitter.com/9Bae9kw8c9 — ESA (@esa) November 20, 2016

Welcome aboard! Watch again as @Thom_astro @AstroPeggy & Oleg enter @Space_Station #Principia https://t.co/1co6u1YNij pic.twitter.com/IuU5OUgKUq — ESA (@esa) November 20, 2016

@LaBombeH @Thom_astro @NASA @CNES Bonne nuit! — ESA (@esa) November 20, 2016

@Kombiice Looks like it! 🙂 — ESA (@esa) November 20, 2016

Press release: ESA astronaut @Thom_astro arrives at the @Space_Station https://t.co/OJJVQYaFDy pic.twitter.com/WDsG3e4GCf — ESA (@esa) November 20, 2016

After hatch opening at 00:40 GMT (01:40 CET), @Thom_astro @AstroPeggy & Oleg entered their home for the next 6 months. https://t.co/F0Me1Ht30v — ESA (@esa) November 20, 2016

Congrats to ur new home @Thom_astro This says you're the 549th human to leave this big blue planet outside ur window https://t.co/ROFOLDQ6wG — Alexander Gerst (@Astro_Alex) November 20, 2016