Vsauce has again a mind blowing video about light and the increased weight bodies have when the light shines on them. When the Sun shines every in2 is pushed by light with about a Billionth of a pond (half a billionth of a kilograms), thus making the city of Chicago heavier by 300 lbs (140kgs).
That might not sound much, but it is enough incentive to start building a Sun Sail. When you travel to Mars you are pushed away by light by 1000 miles. Ok, for a 50 million kilometers travel that might not sound much, but there is potential for light to move objects out of trajectory. I bet you didn’t knew that. Me neither.