The search for'another Earth' has been a staple of science fiction for decades, and now a group of astronomers hope to discover one on our galactic doorstep. Alpha Centauri is a triple star system just over four light years from the Earth, split into a pair of sun-like stars known as AB, and a red dwarf called Proxima Centauri. So far planets have only been found orbiting Proxima Centauri, but experts from the University of Sydney and Breakthrough Initiatives believe they will find a world orbiting the larger binary pair using a new privately funded telescope. Known as the Toliman mission, it will launch in 2023 and scan Alpha Centauri AB for worlds in the habitable zone, where liquid water can flow on the surface. The team hope to be able to say whether there are habitable worlds orbiting either or both of the binary stars by the middle of this decade.

Machine translation of human languages (for example, Japanese, English, Spanish) was one of the earliest goals of computer science research, and it remains an elusive one. Like many AI tasks, translation requires an immense amount of knowledge about language and the world. Recent approaches to machine translation frequently make use of text-based learning algorithms to fully or partially automate the acquisition of knowledge. This article illustrates these approaches. Anyone who has taken a graduate-level course in AI knows the answer.

An illustration shows what a visitor might see if they could stand on the surface of the Earth-size planet Proxima b. Just a few months ago, astronomers revealed that there is an Earth-size world orbiting Proxima Centauri, the next star over. Now, a team of astrophysicists thinks there's a way to pay that planet a nice long visit sometime in the not-so-distant future. The method involves something similar to the Breakthrough Starshot Initiative, a plan unveiled last year that would send a fleet of small spacecraft toward the three stars in the Alpha Centauri system, which includes Proxima. Propelled by a giant laser, those tiny spacecraft would zip through the system in a matter of moments, furiously snapping photos, gathering data, and somehow relaying that information back to Earth.