Nasa turns on Tess spacecraft, starting major search for alien worlds

Nasa has begun a major search for alien worlds. The agency's Tess spacecraft has started its science missions, exploring the universe as it looks for new planets. It engineers hope that it will eventually find thousands of alien worlds, some of which could be habitable. The craft – whose name stands for Transiting Exoplanet Survey Satellite – will look deep in the universe for signs of planets. Any that are found will be explored from afar, as scientists try to work out what it might be like on those planets, and whether life could survive there.