Question

Easy astronomy question?

All the following statements are true. Which of them are considered to be "exceptions" to the general trends described by the first three major characteristics of the solar system? I have to check all that apply:

1)Our Moon has a diameter more than 1/4 the diameter of Earth.

2)Jupiter's largest moon, Ganymede, is even larger than Earth's moon.

3)Pluto is in the outer solar system but is ice-rich in composition.

4)Uranus rotates with an axis tilt that lies nearly in the ecliptic plane.

5)Venus rotates in a direction opposite to the rotation of the other terrestrial planets.

Answers

Number 4 and 5 seem to be the exceptions. Uranus rotates with a 98 degree tilt from the perpendicular and is literally pointing its poles at the earth as it revolves on its 84 year cycle around the sun. If you look at it from this angle then Uranus is rotating retrograde (though not as pronounced as Venus), and therefore number 5 appears to be wrong. Number 3 is interesting because Pluto is now a dwarf planet in the Kuiper Belt and ice-rich seems to be ambiguous to say the least. Incidently, Venus is the only planet to have a longer day (243 days) than its year (225) days--I hope these numbers are correct since I'm dragging them out of my head at this late hour.

#1

I'm guessing the 4 and 5, are the exceptions. I hope you've seen the free on-line programs called: Celestia, and Stellarium.

#2

4 and 5 are the exceptions. It's just their rotations and the first 3 are actually rich facts about the solar system.

#3

1, 4, and 5 trust me

#4