An international team of scientists has recently confirmed an unproven theory that sunlight can effect the rotation of asteroids. It seems that sunlight can cause asteroids to spin quickly. It's called the YORP effect, named after the four scientists (Yarkovsky-O'Keefe-Radzievskii-Paddack) who inspired the theory. The YORP effect is based on a theory that the Sun's heat serves as a propulsion engine, so when sunlight hits the asteroid solar energy is absorbed and then radiated back out to space.
Now let's try to wrap our little brains around this one. One of the asteroids used in this study (2000 PH5) increased its spin by 1 millisecond per year. One day on the asteroid last about 12 Earth minutes and it just keeps getting faster and faster and gaining more energy. The scientists in the article talk about how understanding the YORP effect gives us a better understanding of our solar system.
If the Sun can have that kind of an effect on a lump of metal and rock, then what could we do with that kind of harnessed energy right here on earth?