|Themes > Science > Astronomy > The Solar System > The Solar System > Overview of the Solar System > Revolution and Rotation of the Planets|
The Inner Solar System
The sizes and shapes of the orbits are realistic, as is the relative positions of the planets for the date in the Fall, 1996, when the plot was constructed. The sizes of the planetary symbols are not to scale; the planets would be too small to see at this scale as more than dots of light. Notice the eccentricity of the orbits for Mercury and, to a lesser degree, Mars. From this perspective (which corresponds to looking down on the Northern hemisphere of the Earth), the planets all revolve in a counter-clockwise sense, as indicated by the arrow.
Here are the present positions (to scale) of planets in the inner solar system. In this plot, the portion of orbit in blue is above and the portion in green is below the plane of the ecliptic. As noted in conjunction with Kepler's Third Law, motion of the innermost planets is much faster than that of the outermost.
The preceding views represent a "top" or North perspective. Here is a side perspective of the inner Solar System showing the tilt of the planetary orbits with respect to the plane of the ecliptic.
In this figure the white portion of the orbit is above the ecliptic plane and the yellow portion is below. Notice that the orbits of the inner planets are nearly, but not quite, in the same plane. The orbit of Mercury, in addition to being the most eccentric, has the largest tilt (7 degrees) with respect to the ecliptic plane.
The Entire Solar SystemHere is the entire Solar System to scale for the orbits, also in the Fall, 1996:
Notice the enormous amount of empty space in the outer Solar System. To show the entire Solar System to scale, the inner Solar System becomes so compressed that the planet orbits almost appear to run together. The very large eccentricity of Pluto's orbit is also obvious.
Here are the present positions (top view, to scale) of all planets in the Solar System. As above, the portion of orbit in blue is above the plane of the ecliptic; portion in green is below the plane of the ecliptic.
The following figure shows the full Solar System to scale from a side view to illustrate the tilt of the orbits.
Notice that Pluto's orbit is highly tilted (17 degrees) relative to the plane of the ecliptic.
Here is the average separation of the planets from the Sun (in astronomical units) displayed in graphical form,
and here are the eccentricities of the planetary orbits
These two graphs display clearly the enormous distances in the outer Solar System, and that Pluto and Mercury have by far the most elliptical orbits.