The "StarShot" project press conference is held at One World Observatory in New York, the United States on April 12, 2016. British astrophysicist Stephen Hawking announced here he is teaming up with Russian billionaire Yuri Milner and a group of scientists for a new "Starshot" space exploration program, which will build tiny spacecraft called "nanocrafts" capable of reaching the Alpha Centauri star system in approximately 20 years after launch. (Xinhua/Li Changxiang)