The NASA/NIVR IRAS satellite and the NRO/USN POPPY 5B satellite (aka GGSE 4) are predicted to make a close approach on Wednesday. POPPY 5B has 18-metre-long gravity gradient booms so a 15-to-30 metre predicted miss distance is alarming https://t.co/H1UckcoaAH

— Jonathan McDowell (@planet4589) January 27, 2020