Eight Planets to the Solar System
Today, the neighbourhood has shrunk. Our solar system now has eight planets and not nine: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
Pluto is no longer considered a planet.
Source.
ETA: The new definition of a planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."
ETA2: Pluto hasn't cleared the neighbourhood. It crosses paths with Neptune. Photo. {Source: CNN}
ETA3: Pluto hasn't cleared the neighbourhood. The problem, says dougs {Mathematician}, is this: "Pluto and Charon are in each other's orbital neighbourhood -- they accompany each other around the sun. Neither has succeeded in clearing away the other. (They don't qualify as a planet with a moon, since their common centre of gravity doesn't lie beneath Pluto's surface)." <- Folks, this needs clarification. Does anybody know which is the correct one?
|Meduza|
Pluto is no longer considered a planet.
Source.
ETA: The new definition of a planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ... nearly round shape, and has cleared the neighborhood around its orbit."
ETA2: Pluto hasn't cleared the neighbourhood. It crosses paths with Neptune. Photo. {Source: CNN}
ETA3: Pluto hasn't cleared the neighbourhood. The problem, says dougs {Mathematician}, is this: "Pluto and Charon are in each other's orbital neighbourhood -- they accompany each other around the sun. Neither has succeeded in clearing away the other. (They don't qualify as a planet with a moon, since their common centre of gravity doesn't lie beneath Pluto's surface)." <- Folks, this needs clarification. Does anybody know which is the correct one?
|Meduza|