Free Astronomy Magazine September-October 2019

THE FREE MULTIMEDIA MAGAZINE THAT KEEPS YOU UPDATED ON WHAT IS HAPPENING IN SPACE Bi-monthly magazine of scientific and technical information ✶ September-October 2019 ✶ ✶ K dwarfs, the best target for biosignatures The Tunguska event, now rarer than expected • La Silla 50 th anniversary culminates with total solar eclipse • The early days of the Milky Way revealed by Gaia • First 18 ELT primary mirror blanks arrive at Safran Reosc • NEAR experiment sees first light • “Moon forming” circumplanetary disk in a distant star system La S th instru Space radiation − a deadly obstacle