Question

If the Earth's axis of rotation was inclined at 90 degrees what would happen?

a.) Earth would experience no seasons
b.) A frozen equator throughout the year
c.) Frozen poles throughout the year
d.) The hemispheres would have their seasons reversed
e.) Only one hemisphere would permanently face the Sun

Answer 1

The most likely answer is c) frozen poles throughout the year.

Explanation:

The Earth's axis is currently tilted at an angle of about 23.5 degrees. This lead to 5 important circles of latitude. These are the Arctic and Antarctic circles, the Tropics of Cancer and Capricorn and the Equator.

This leads to the Earth having different zones.

The tropics which lie between the Tropics of Cancer and Capricorn have equal length days and nights and no seasons as such. Weather systems do however bring wet and dry seasons.

The temperate zones between the Tropics and the Arctic Circles have distinct seasons. They have longer, warmer Summer days and shorter, colder Winter nights.

The Arctic regions have 24 hour Summer days and 24 hour Winter nights. They are covered in ice caps because the warmer Summers are not long enough to melt the ice which is added to by the colder Winters.

If the Earth's axial tilt were 90 degrees, then the Equator, Tropics and Arctic circles would all be in the same place. The tropical and temperate zones would be a thin band around the equator. Each hemisphere would experience 24 hour days in Summer and 24 hour Winter nights.

There would almost certainly be ice caps over both poles throughout the year. The Antarctic ice cap would definitely be much larger than it is at the current tilt. The North pole could possibly melt in Summer.

To answer the events:
a.) Earth would experience no seasons
This is only possible if the axial tilt was 0 degrees

b.) A frozen equator throughout the year
This is only possible if the whole planet was frozen throughout the year.

c.) Frozen poles throughout the year
This is the most likely event, though the North pole could melt during Summer.

d.) The hemispheres would have their seasons reversed
This is not possible unless something flipped the Earth upside down like Venus.

e.) Only one hemisphere would permanently face the Sun
This is totally impossible as it violates the law of conservation of angular momentum.