This was an image I did for the July 1999 edition of UK magazine Frontiers, to illustrate a solar sail. Solar sails are gigantic sheets of highly reflective but wafer-thin material. They intercept photons — particles of light — from the Sun, and the pressure from this pushes the craft through space. This picture depicts a circular-design sail flying past Halley's comet at the next encounter in 2061. See also Jovian Flyby.