Free Astronomy Magazine March-April 2015

project leads. NGTS is designed to operate in a robotic mode and it will continuously monitor the brigh- tness of hundreds of thousands of compar- atively bright stars in the southern skies. It is searching for tran- siting exoplanets and will reach a level of accuracy in measuring the brightness of stars — one part in a thou- sand — that has never before been attained with a ground- based wide-field survey instrument. (NASA’s orbiting Kepler mission has a higher accuracy of stellar brigh- tness measurement but probes a smaller region of the sky than NGTS. The wider NGTS search will find brighter examples of small exoplanets that are better suited for detailed study.) SPACE CHRONICLES T his time-lapse sequence shows the system during testing under a brilliant Moon. [ESO/G. Lambert] This great accuracy of brightness measure- ment, across a wide field, is technically demanding, but all the key technologies needed for NGTS were demonstrated using a smaller prototype sys- tem, which operated on La Palma in the Canary Islands during 2009 and 2010. NGTS also builds on the suc- cess of the Super- WASP experiment, which up to now leads in the detection of large gaseous plan- ets. The discoveries of NGTS will be studied further using other larger telescopes, in- cluding the ESO Very Large Telescope. One goal is to find small T he Next-Generation Transit Survey (NGTS) is located at ESO’s Paranal Observatory in northern Chile. This project will search for transiting exoplanets — planets that pass in front of their parent star and hence produce a slight dimming of the star’s light that can be detected by sensi- tive instruments. The telescopes will focus on discovering Neptune-sized and smaller planets, with diameters between two and eight times that of Earth. This image shows the NGTS enclosure in the day. The VISTA (right) and VLT (left) domes can also be seen on the horizon. [ESO/R. Wesson] serving conditions and excellent support facilities available at this site. “We needed a site where there were many clear nights and the air was clear and dry so that we could make very accurate measurements as often as possible — Paranal was the best choice by far,” says Don Pollacco of the University of War- wick in the UK and one of the NGTS