Who discovered Pluto: Robert McMillan, Johann Gottfried Galle, Clyde W. Tombaugh or Annibale de Gasparis?

How many moons does Mars have?

Which planet is known as the Red Planet?

In what year was Array of Low Energy X-ray Imaging Sensors launched: 1974, 1983, 1993 or 1999?

In what year was 13P/Olbers discovered: 1811, 1812, 1815 or 1823?

In what year was NGC 6109 discovered: 1836, 1864, 1880 or 1888?

In which constellation is HD 131496 located: Eridanus, Carinae, Boötes or Ursa Minor?