Three thousand light-years from Earth sits Kepler 160, a sun-like star that’s already thought to have three planets in its system. Now researchers think they’ve found a fourth. Planet KOI-456.04, as it’s called, appears similar to Earth in size and orbit, raising new hopes we’ve found perhaps the best candidate yet for a habitable exoplanet that resembles our home world. The new findings...

When the Dallas police called for the public to send them videos of illegal activity during protests a week ago, they didn’t get the evidence of law-breaking demonstrators they expected. Instead, fans of Korean pop music downloaded the police department’s app en masse, rallied each other to flood it with short, fan-produced videos, and gave…

With dozens of digital contact tracing apps already rolled out worldwide, and many more on the way, how many people need to use them for the system to work? One number has come up over and over again: 60%.  That’s the percentage of the population that many public health authorities documented by Technology Review’s Covid Tracing Tracker say they are targeting as they attempt to protect...