Paraules clau: Caront, Clyde Thombaugh, Mart, Neptú, Percival Lowell, Plutó, Saturn, Telescopi Hubble, Urbain LeVerrier
Paraules clau: Giovanni Schiaparelli, Mart, Percival Lowell, Sol
Paraules clau: asteroide, Friedrich Bessel, Giovanni Schiaparelli, Heinrich Olbers, Josep Comas, Mart, Percival Lowell