#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

#Galileo goes live – Europe’s own #satnav system begins serving the world https://t.co/lCu5yAHHQj https://t.co/VAA1Jf72hP — ESA (@esa) December 15, 2016

The #GalileoGoesLive button is pressed! From now on Europe's #Galileo #satnav system is providing services to users worldwide pic.twitter.com/OAnwd1a8bq — ESA Technology (@ESA_Tech) December 15, 2016

#Galileo family gathered on stage, with @EBienkowskaEU and @janwoerner about to press #GalileoGoesLive button pic.twitter.com/ImUEVoQJmS — ESA Technology (@ESA_Tech) December 15, 2016

"Thank you everyone on Twitter" A year since his launch, watch @astro_timpeake reflect on his time in space 🚀 pic.twitter.com/qN2o40Y49Z — Twitter UK (@TwitterUK) December 15, 2016

VID: Where do astronauts sleep? @Thom_astro shows us his space bedroom https://t.co/cg4v3sC85P — ESA (@esa) December 15, 2016

This is tonight’s “#supermoon” seen from space! The last one I saw was in Baikonur… I like this one better! 😉 https://t.co/duazK4PrVt pic.twitter.com/luehtC4sAJ — Thomas Pesquet (@Thom_astro) December 14, 2016

#BajaCalifornia is a popular resort destination, but also a sanctuary for nature. And very photogenic! https://t.co/ROgBUJ4XvC #Proxima 🇲🇽 pic.twitter.com/ZKgy7mCTak — Thomas Pesquet (@Thom_astro) December 14, 2016

Orion main engine arrives in Europe https://t.co/AKSoNOC66d pic.twitter.com/PRPc2NoU9E — ESA (@esa) December 14, 2016