17th & 18th #Galileo satellites enter operations as part of Europe's #satnav constellation, overseen by @EU_GNSS https://t.co/QLz2oCbCVi pic.twitter.com/HLFocuN2Lq — ESA Technology (@ESA_Tech) August 11, 2017

Book belongs to Helen Sharman who took it with her to Mir in 1991 https://t.co/LPa6Kon7MX — ESA (@esa) August 11, 2017

Not sure it's up for donation, but @astro_timpeake had copy of Gagarin's "The Road to the stars" with him in space for 6 months pic.twitter.com/Jf5HbdVlam — ESA (@esa) August 11, […]

📌Due to many requests, the submission deadline for the #Business #Idea #Competition has been extended to 3 September https://t.co/MdQzpCuNtO pic.twitter.com/V9E7k2Wpte — ESA ARTES (@esa_artes) August 11, 2017

We'll be sharing some news about that soon! — ESA (@esa) August 11, 2017

The @ESA_EO #EarthFromSpace programme returns in September – meanwhile you can rewatch all past episodes here… https://t.co/AYkUvxs10w — ESA (@esa) August 11, 2017

¡Hola #Canarias ! Has anyone seen us from Roque de los Muchachos Observatory in La Palma? #VITAmission #EarthfromSpace pic.twitter.com/J7hnAdmLa7 — Paolo Nespoli (@astro_paolo) August 11, 2017

A darkened sky holds bright planet Venus, the New Moon in silhouette, and the shimmering corona of the Sun in this image of a total solar eclipse. A composite of […]

Look up for the #Perseids over the next few nights! https://t.co/A0UDWkTm24 — ESA (@esa) August 10, 2017