Families of Solar systmem

 Let's learn about families of solar system.
1.Sun
Firstly, there is king of solar system, the Sun. Sun's mass is 99.8% of whole solar system's mess. Its surfacs's temperature is about 6000 degrees Celsius. And we can see many black points on the sun's surface. It's called "Sunspots" Sunspot is area that cold than usual sun's surface.  Sunspots' temperature is about 4000 degrees Celsius. Sun's gravity makes planets to turn the Sun. Sun's gravitational field's radius is about 2 light-year.

 

2.Planets

 There are 8 planets in solar system. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune are 8 planets. Jupiter is the biggest planet in solar system. Saturn is 2nd, Uranus is 3nd, Neptune is 4nd(But Neptune is heavier than Uranus).

This is planets' mass porpotation graph.

Bluish green is Jupiter, orange is Saturn, brown is Neptune, pale blue is Uranus. Mercury, Venus, Earth, Mars are rocky planet. It has a land that you can walk. Rocky planets are small and have big density.

And Jupiter, Saturn, Uranus, Neptune are called "Gas Giant" They are big and they are not rocky. They have lots of gas. So they don't have a land that you can walk. They have small density.

 

 




3.Dwarf planets
 Dwarf planets can keep sphere shape by its gravity, but it can't be planets. They are smaller than planets. Pluto is typical dwarf planets. Pluto was planet, but it changed to dwarf planets. Because one object that is heavier than pluto was discovered.(Eris). And many object that similar to Pluto were discovered. So we must add many palnets. So Astronomers made new level called "dwarf planet" How do we classify planets and dwarf planets? These are define of planet. If some object want to be a planet, it must satisfy does 3 conditions.

 1.Objects with true masses below the limiting mass for thermonuclear fusion of deuterium (currently calculated to be 13 times the mass of Jupiter for objects with the same isotopic abundance as the Sun) that orbit stars or stellar remnants are "planets" (no matter how they formed). The minimum mass and size required for an extrasolar object to be considered a planet should be the same as that used in the Solar System.

 2.Substellar objects with true masses above the limiting mass for thermonuclear fusion of deuterium are "brown dwarfs", no matter how they formed or where they are located.

 3.Free-floating objects in young star clusters with masses below the limiting mass for thermonuclear fusion of deuterium are not "planets", but are "sub-brown dwarfs" (or whatever name is most appropriate).

These are dwarf planets.

Pluto and its moon "Caron"
Cedna 
Haumea It's looks like a egg.
Qauoar
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4. Asteroids

Asteroids are very small. It can't keep sphere share. They are almostly gathered between Mars and Jupiters. It called "Asteroid belt"

 

5.Comet

Comet is consisted by dirty ice and rock. Representative comet is Halley's comet. It turns the Sun. Its orbit is ellipse. When it is near to the sun, it get a big and blue tail offside of the sun.