Planets that have been *orbited* by spacecraft:
* Mercury:
* MESSENGER (2011-2015) This NASA spacecraft was the first to orbit Mercury, providing detailed maps and data about its surface, composition, and magnetic field.
* Venus:
* Magellan (1990-1994) This NASA mission used radar to map Venus's surface, revealing its volcanic features, craters, and mountains.
* Venus Express (2006-2014) A European Space Agency mission that studied Venus's atmosphere and climate.
* Mars:
* Many missions! Mars is the most explored planet, with multiple orbiters from NASA, ESA, and other space agencies.
* Some notable examples include the Mars Reconnaissance Orbiter, the Mars Odyssey, and the Mars Express.
* Jupiter:
* Juno (2016-present) This NASA spacecraft is currently orbiting Jupiter, studying its magnetic field, atmosphere, and internal structure.
* Saturn:
* Cassini (2004-2017) This joint NASA/ESA/ASI mission orbited Saturn for over a decade, providing stunning images of its rings and moons.
* Uranus:
* Voyager 2 (1986) This NASA mission flew past Uranus, providing the first close-up images of the planet and its rings.
* Neptune:
* Voyager 2 (1989) This NASA mission flew past Neptune, providing the first detailed observations of the planet and its moon Triton.
Planets that have been *landed on* by spacecraft:
* Venus:
* Venera series (1960s-1980s) A series of Soviet probes that successfully landed on Venus, returning data about its surface and atmosphere.
* Mars:
* Many landers! Mars has hosted a variety of landers and rovers from NASA, including:
* Viking 1 and 2 (1976) The first successful landers on Mars, which conducted experiments to search for signs of life.
* Sojourner (1997) The first rover on Mars, part of the Pathfinder mission.
* Spirit and Opportunity (2004-2018) Two rovers that explored Mars for years, making significant discoveries.
* Curiosity (2012-present) This rover is currently exploring Mars, studying its geology and habitability.
* Perseverance (2021-present) The latest rover on Mars, focusing on searching for signs of past life and collecting samples for future return to Earth.
Planets that have only been *flown past* by spacecraft:
* Pluto:
* New Horizons (2015) This NASA mission flew past Pluto, providing the first close-up images of this dwarf planet and its moons.
Important Note: While we have explored all the planets in our solar system, our understanding of them is still developing. New missions and data continue to refine our knowledge.
