Free Astronomy Magazine January-February 2018

35 JANUARY-FEBRUARY 2018 SPACE CHRONICLES the Sun. Both belts are much further from Proxima Centauri than the planet Proxima b, which orbits at just four million kilometres from its parent star. Guillem Anglada ex- plains the implications of the discov- ery: “This result suggests that Proxima Centauri may have a multiple planet system with a rich history of interactions that resulted in the formation of a dust belt. Further study may also provide information that might point to the loca- tions of as yet unidentified additional planets.” Proxima Centauri’s planetary system is also particularly in- teresting because there are plans — the Starshot project — for future direct explo- ration of the system with mi- croprobes attached to laser-driven sails. A knowledge of the dust envi- ronment around the star is essential for planning such a mission. Co-author Pedro Amado, also from the Instituto de Astrofísica de An- dalucía, explains that this observa- tion is just the start: “These first results show that ALMA can detect dust structures orbiting around Proxima. Further observations will give us a more detailed picture of Proxima’s planetary system. In combination with the study of pro- toplanetary discs around young stars, many of the details of the processes that led to the formation of the Earth and the Solar System about 4600 million years ago will be unveiled. What we are seeing now is just the appetiser compared to what is coming!” T his artist’s impression shows how the newly discovered belts of dust around the closest star to the Solar System, Proxima Centauri, may look. ALMA observations revealed the glow coming from cold dust in a re- gion between one to four times as far from Proxima Centauri as the Earth is from the Sun. The data also hint at the presence of an even cooler outer dust belt and indicate the presence of an elaborate planetary system. These structures are similar to the much larger belts in the Solar System and are also expected to be made from particles of rock and ice that failed to form planets. Note that this sketch is not to scale — to make Proxima b clearly visible it has been shown fur- ther from the star and larger than it is in reality. [ESO/M. Kornmesser] T his artist’s video impression shows how the newly discovered belts of dust around the closest star to the Solar System, Proxima Centauri, may look. [ESO/M. Kornmesser] !