1 Thorium fuels can breed fissile uranium-233 to be used in various kinds of nuclear reactors. 2  Molten salt reactors are well suited to thorium fuel, as normal fuel fabrication is avoided.
Since Pluto has a much higher axial tilt of roughly 119.5 degrees, it has much larger arctic and antarctic circles, each stretching from roughly 29.5 degrees latitude to their respective poles. This means that at the peak of Plutoâs summer the area receiving the most direct sunlight is actually in the arctic circle.
The tilt of the Earth's spin axis with respect to the plane of its orbit about the sun (the ecliptic plane) is important for a habitable Earth. The Earth's spin axis is tilted 23.5Â° with respect to the ecliptic, giving moderate seasons and preventing temperature extremes anywhere on the planet. This illustration, patterned after Ward and Brownlee, summarizes the effects of different tilt angles with respect to the ecliptic plane.