Mercury (planet) Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the gods. Like Venus, Mercury orbits the Sun within Earth's orbit as an "inferior planet", and never exceeds 28° away from the Sun. When viewed from Earth, this proximity to the Sun means the planet can only be seen near the western or eastern horizon during the early evening or early morning. At this time it
Outer Planet Flagship Mission Outer Planet Flagship Mission The Outer Planet Flagship Mission is a type of NASA program to research larger size missions to the outer solar system, and some examples of this type of mission are Galileo or Cassini-Huygens. In 2013 after encounter some technical issues and funding in the early 2010s, development was paused although overall research continued. One issue is the other big NASA missions such as in astrophysics and another is availability of RTG's One proposal was a joint mission between NASA and ESA to send a probe to study the icy satellites of the outer Solar System. There