Mammatus Clouds over Mount Rushmore via NASA https://j.mp/3lQNPDJ https://j.mp/346H0YL

Mammatus Clouds over Mount Rushmore via NASA https://t.co/2jMYDTAhdN pic.twitter.com/Iw6Z0xVVji

— しらいはかせ #XRKaigi2020 (12/10 15時) #CCSE2020 登壇予定 (@o_ob) December 7, 2020