Free Astronomy Magazine September-October 2019

38 SEPTEMBER-OCTOBER 2019 SPACE CHRONICLES “Moon forming” circumplanetary disk in a distant star system A LMA image of the dust in PDS 70, a star system located approximately 370 light-years from Earth. Two faint smudges in the gap region of this disk are as- sociated with newly formed plan- ets. One such concentration of dust is a circumplanetary disk, the first such feature ever detected around a distant star. [ALMA (ESO/NAOJ/NRAO); A. Isella] A stronomers using the Ata- cama Large Millimeter/sub- millimeter Array (ALMA) have made the first-ever observa- tions of a circumplanetary disk, the planet-girding belt of dust and gas that astronomers strongly theorize controls the formation of planets and gives rise to an en- tire system of moons, like the one found around Jupiter. This young star system, PDS 70, is located ap- proximately 370 light-years from Earth. Recently, astronomers con- firmed the presence of two mas- sive, Jupiter-like planets in orbit around the star. This discovery was made with the European Southern Observatory’s Very Large Telescope (VLT), which detected the warm glow natu- by ALMAObservatory