Spain's Queen Letizia, left, walks with Juliana Awada, the wife of the Argentina's President Mauricio Macri, during a welcome ceremony at the Royal Palace in Madrid.
This illustration shows the possible surface of TRAPPIST-1f, one of the newly discovered planets in the TRAPPIST-1 system. Scientists using the Spitzer Space Telescope and ground-based telescopes have discovered that there are seven Earth-size planets in the system.
Internally displaced people sit at a makeshift camp for IDPs in al-Jarahi, south of the Red Sea port city of Houdieda, Yemen.
Elena's, from Dresden, hair ruffled by the wind as she stands on a visitors' platform on the Maintower in Frankfurt am Main, western Germany, during stormy weather.