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.
A planet's axial tilt is a measure of whether the planet is in prograde (the natural direction of rotation of most bodies in our solar system) or retrograde (the opposite, ie, from East to West) rotation. Tilt angle is measured relative to the orbital plane of a planet. A tilt between 1 to 90 degrees is considered prograde rotation (Earth's tilt is 23 degrees, in prograde rotation), a tilt of 90 degrees is considered perpendicular, and neither prograde or retrograde.