Question

Consider the first major feature (orderly motions). Which of the following correctly describe patterns of motion in our solar system? Select all that apply.
(a) The Sun and most of the planets rotate in the same direction that the planets orbit.
(b)Major moons generally have polar orbits, meaning orbits that take them over the north and south poles of the planet they orbit.
(c) Planets have nearly circular orbits.
(d)The outer planets are so large that they nearly collide with each other on each orbit.
(e)All the planets orbit the Sun in nearly the same plane.
(f) Inner planets orbit the Sun in the opposite direction from the outer planets

Answer 1

Answer:

(a), (c), (e)  

Explanation:

(a) The Sun and most of the planets rotate in the same direction that the planets orbit.

The Sun and most of the planets rotates in the same direction (counter-clockwise) as a consequence of the conservation of the angular momentum from the could in which they were formed.

However, Venus and Uranus rotate in retrograde motion (clockwise), it is  thought that is due to the collision with an asteroid in the early days of both planets.

(b) Major moons generally have polar orbits, meaning orbits that take them over the north and south poles of the planet they orbit.

Polar orbits are not common between major moons, They follow orbits related to the plane of the Solar System.    

(c) Planets have nearly circular orbits.

Kepler's first law establishes:

All the planets revolve around the Sun in an ellipse orbit, with the Sun in one of the focus.

The ellipse has a low eccentricity in the case of planetary orbits.

(d) The outer planets are so large that they nearly collide with each other on each orbit.

They have enough space between them, so it is not possible a collision.

For example, lets take the example of the diameter on Jupiter and Saturn. The diameter of Jupiter is 139.820 Km while Saturn has a diameter of 116.460 Km.

The distance of Saturn from the Sun is 9.5 AU (AU = Astronomical Unit) while in Jupiter is 5.1 AU.

1 AU is defined as the distance between the Earth and the Sun ($1.50x10^{8} Km$)

The distance of Saturn from the Sun in Kilometers:  

$d_{saturn} = 9.5 AU . \frac{1.50x10^{8} Km}{1AU}$

$d_{saturn} = 1.425x10^{9} Km$

The distance of Jupiter from the Sun in Kilometers:

$d_{saturn} = 5.1 AU . \frac{1.50x10^{8} Km}{1AU}$

$d_{saturn} = 7.65x10^{8} Km$

Distance between the two planets:

$d_{J-S} = 1.425x10^{9} Km -7.65x10^{8} Km$

$d_{J-S} = 6.60x10^{8} Km$

If the distance between the planets is compared with the diameters of any of them, it is easy to see that the planets can't be in a collision since they don't fill the space between them with its diameter.

In the case of Jupiter:

$diameter_{Jupiter}$ $<$ $d_{J-S}$

$139.820 Km$ $<$ $6.60x10^{8}$

In the case of Saturn:

$diameter_{Saturn}$ $<$ $d_{J-S}$      

$116.460 Km$ $<$ $6.60x10^{8}$    

(e)All the planets orbit the Sun in nearly the same plane.

When the cloud, from were the planets form, collapse, it starts to rotate and accrete the material in a disk. Given as a result that the planets were in nearly the same plane.

It is important to consider that planets have different degrees of orbital inclinations, which is due to interactions with others object while its formation.

(f) Inner planets orbit the Sun in the opposite direction from the outer planets

This is not correct. Inner planets are constituted by Mercury, Venus, Earth, and Mars.

Mercury, Earth and Mars share the counter-clockwise direction as some outer planets, while Venus shares the same retrograde motion as Uranus.