Answer to Question 1
Flopped over with a 98 degree tilt, Uranus' pole was pointing toward the Sun at solstice in 1986 when Voyager 2 flew past. With one hemisphere in constant daylight, the atmosphere was very bland. But by equinox in 2008, the whole planet was receiving eight hours of day and night, and the heating patterns were producing more normal jovian belts and zones. At each pole, you would get 42 years of constant Sun, then 42 years of darkness.
Answer to Question 2
When the electron orbiting the proton in hydrogen flips its spin, the energy radiated has a wavelength of 21 cm, and is detected with radio telescopes.