Twyman Clements, 31, co-founder and chief executive, Space Tango

The world appears to be on the cusp of an explosion in personal and passenger air travel and commercial exploitation of space. It’s exciting, but the environmental and societal concerns of the coming revolution need to be considered starting now. Aerospace expert Amir S. Gohardani explains.

Scientists are detecting exoplanets daily by the slight decrease in light from a host star as a planet transits in front of it. Photos of such a planet could tell us whether or not we are alone in the universe. Louis D. Friedman and Slava G. Turyshev think they have a solution for delivering this photographic evidence, one that will require a 900 trillion-kilometer journey and applying a phenomenon discovered by Einstein.