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DaveC426913
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This came up in https://www.physicsforums.com/showthread.php?t=119891", and now I'm not sure of my answers.
1] Venus' rotation is retrograde. Is that taking into account its revolution about the Sun, or is that still true from and external point-of-view?
i.e.: If the Sun were suddenly whisked out of existence, and Venus were left adrift on a straight path, it would continue to rotate slowly on its axis:
a] clockwise
b] counterclockwise
2] Venus' axial tilt is ~178 degrees. this is because
a] Axial tilt is always defined with North magnetic pole being at the top. Since on Venus, the South magnetic pole is at the top, the axial tilt is measured as upside down (i.e. ~180 from upright).
b] Axial tilt is always defined with North rotating counterclockwise. Because Venus is retrograde, its "bottom" pole is actually the one rotating counterclockwise, and thus is considered the North pole, which means Venus is upside down (i.e. ~180 from upright).
Here's the thing about 2b. If true, you can't say Venus is BOTH retrograde AND upside down; it can be considered one OR the other, but to count both is basically double-dipping.
1] Venus' rotation is retrograde. Is that taking into account its revolution about the Sun, or is that still true from and external point-of-view?
i.e.: If the Sun were suddenly whisked out of existence, and Venus were left adrift on a straight path, it would continue to rotate slowly on its axis:
a] clockwise
b] counterclockwise
2] Venus' axial tilt is ~178 degrees. this is because
a] Axial tilt is always defined with North magnetic pole being at the top. Since on Venus, the South magnetic pole is at the top, the axial tilt is measured as upside down (i.e. ~180 from upright).
b] Axial tilt is always defined with North rotating counterclockwise. Because Venus is retrograde, its "bottom" pole is actually the one rotating counterclockwise, and thus is considered the North pole, which means Venus is upside down (i.e. ~180 from upright).
Here's the thing about 2b. If true, you can't say Venus is BOTH retrograde AND upside down; it can be considered one OR the other, but to count both is basically double-dipping.
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