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urmomaisjabbathehutt t1_ixa2l8w wrote

Reply to comment by leojg in Vast volcanic eruptions may have turned Venus from paradise into hell by pecika

Something happened to make the whole planet north roll south so that it ended with what we have now rotating backwards

maybe before its original rotation direction and period was ok

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mr_bedbugs t1_ixapbr9 wrote

Is Venus upside down, or does it just spin backwards?

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urmomaisjabbathehutt t1_ixb3izl wrote

Being hit by something that flipped it upside down is one of several hypothesis for both venus and Uranus, other hypothesis are atmospheric tidal torques along being hit ......etc, etc, so yea there is a chance that something did flipped it upside down and messed its rotation, but we don't know enough yet to confirm the actual cause

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EarthSolar t1_ixbkvr4 wrote

Both are the same, it just depends on how you define 0 degrees tilt. If you define it as the direction of rotation (north pole is the pole where the planet pins counter clockwise when you look down on it), it’s upside down. If you define it by direction (north pole is the pole that points in the same direction as Earth’s), it spins backward.

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urmomaisjabbathehutt t1_ixciji8 wrote

You may end with same results but it's not about definition, its the actual event

did an impact (or impacts) flipped the planet 180 degrees or did it made it rotate the opposite direction? We can argue that Uranus ended sidewise 90 degrees so flipping is a compelling possibility but we don't have yet enough data to show a definitive answer

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EarthSolar t1_ixd7c9q wrote

I’m responding to the other person.

A lot of things in planetary science can be handwaved away with impacts, that doesn’t mean it’s the correct answer for everything. Tidal-locking, atmospheric tides, rotation instability at very low rotation rates, are also present.

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