The #Arecibo message* could be detected up to about 12,000 light-years away from the Earth which is nearly halfway to the galactic centre (the #MilkyWay 🌌 is 105,700 light-years in diameter and the #SolarSystem is 26,000 light-years from the galactic centre). However, since Arecibo message was broadcasted in 1974, it has travelled only about 50 light-years 📏 so far https://www.scientificeuropean.co.uk/sciences/space/how-far-human-civilisation-is-detectable-in-space
* The message was aimed at #Messier13, about 25,000 light years from Earth https://en.wikipedia.org/wiki/Arecibo_message
The globular star cluster Messier 13 earlier tonight. Result of 3600 0.1-sec images made with my phone and (non-tracking) 20 cm f/3.8 telescope, combined in Siril and the background and color touched up in Gimp. Conditions at my moderately light-polluted site were okay but not great; transparency was poor. The colors of the stars in the image are subtle, just enough to tell the yellowish Red Giant Branch stars from the bluer Horizontal Branch and upper Main Sequence stars.
Spaceflight 🚀
Dr. John Barentine FRAS
JD Gadina 🦄
Voyageur
Alex
Thomas Hanrath
astrofotografie
