Venus rotates in the opposite direction as Earth, and Uranus' spin axis is inclined 90 degrees. Scientists aren't sure how these planets got this way, but they have some ideas.

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction. Credit: 3D motion - stock.adobe.com ...

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction. Credit: 3D motion - stock.adobe.com ...

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction. Credit: 3D motion - stock.adobe.com ...

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction.

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction.

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction. Credit: 3D motion - stock.adobe.com ...

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction. Credit: 3D motion - stock.adobe.com ...

A study suggests the Earth’s inner core, which rotates independently from Earth’s surface, slowed down — but it didn’t stop or reverse direction.