A lonely tree on the background of a cosmological landscapeA lonely tree on the background of a cosmological landscape
Eavesdropping on outer space- search ????other civilizations have been going on for 50 years, but the results are scantyEavesdropping on outer space- search ????other civilizations have been going on for 50 years, but the results are scanty
Separation of the earth and the night sky, light on the horizonSeparation of the earth and the night sky, light on the horizon