questionedithistorytranslationsHow long is stellar year on Mars?687 Earth days609423 Earth days341183 Earth days366121 Earth days738The Martian year is almost twice longer than Earth's year.Share and bring new players to the game!correct this questionTschukareach: rather globalastronomyMarsplanetsKevin Gillwikipedia → MarsPlanets quizAstronomy quizOlympus Mons is the largest known volcano. Where is it?On Mars. Olympus Mons (Latin for Mount Olympus) is a large shield volcano on the planet Mars, having a height of nearly 22 km (14 mi). Being a shield volcano, it has a very low profile. The average slope on the volcano's flanks is only 5°. Because of that, an observer standing on the Martian surface would be unable to view the entire profile of the volcano, even from a great distance.Which rover was the first to explore Mars?Sojourner was the first Mars rover. It was much smaller then Curiosity, whose wheel is about the size of the whole Sojourner. It landed on July 4, 1997 as part of Mars Pathfinder mission on Mars's Ares Vallis and remainded in contact with Earth till September 27, 1997.Mars colonisation is a hype topic. What is the biggest threat for those wishing to take a part in a journey to Mars?Cosmic rays. The only efficient protection against high energetic cosmic radiation, one we are granted with, is Earth magnetic field. Both during a long flight to Mars and through the stay on the planet, that did not form electromagnetic field, astronauts would be exposed to ionization. Most of the planets of the solar system were known in antiquity. Which was the first discovered in modern times with a telescope?Uranus. Like the classical planets, Uranus is visible to the naked eye, but it was never recognised as a planet by ancient observers because of its dimness and slow orbit. Sir William Herschel announced its discovery on 13 March 1781, expanding the known boundaries of the Solar System for the first time in history and making Uranus the first planet discovered with a telescope.