How #Galileo initial services will be serving European and global citizens #GalileoGoesLive https://t.co/lExPajSzqP — ESA (@esa) December 15, 2016

Peggy opening the HTV hatch! We know lots of stuff for us is inside, so it’s good times onboard! https://t.co/MzjMwAyVfV #Proxima pic.twitter.com/WUshI71dK9 — Thomas Pesquet (@Thom_astro) December 15, 2016

#Rosetta and #ExoMars in the top 10 on @Livestream 2016 https://t.co/Red6fRsizS — ESA (@esa) December 15, 2016

Blast off! #OnThisDay in 2015 @astro_timpeake launched to space. 11,000 visitors & @BBCStargazing joined us to watch https://t.co/gu9oNrOah1 — Science Museum (@sciencemuseum) December 15, 2016

#ESATech image of the week: #Proba-V technology-testing minisatellite overflies Mount #Everest https://t.co/K5UF5xvzD1 pic.twitter.com/ubtxnA4AAI — ESA Technology (@ESA_Tech) December 15, 2016

Like details? Our in depth #Rosetta blog has more images & science from @ESA_Rosetta's last days at comet #67P https://t.co/7HTk3THJr9 pic.twitter.com/7QPRTWETD5 — ESA Science (@esascience) December 15, 2016

#Rosetta's last words – a first look at the #science collected during #CometLanding descent to #67P https://t.co/QCWM0dvA4O pic.twitter.com/2vfEUPW24n — ESA (@esa) December 15, 2016

Time flies, especially on @Space_Station ! https://t.co/RKvZ3hcBTu — ESA (@esa) December 15, 2016

#Europe's #Galileo Satellite System begins serving the globe, thanks to @EU_Commission, @EU_GNSS & @ESA – thumbs up! https://t.co/uUQNuYm3Bw pic.twitter.com/1odhWvtlSe — Jan Woerner (@janwoerner) December 15, 2016

Which of these places most captures your curiosity? Write essay for #Cassini Scientist for a Day competition & win! https://t.co/F0LDmMY0Ps pic.twitter.com/qvR29p88xK — ESA Science (@esascience) December 15, 2016