Using tens of thousands of stars observed by the Gaia space probe, astronomers from MPIA and Chalmers have revealed the 3D shapes of two large star-forming molecular clouds, the California Cloud and the Orion A Cloud. In conventional 2D images, they appear similarly structured, containing filaments of dust and gas with seemingly comparable densities. In 3D, however, they look quite distinct. In fact, their densities are much more different than their images projected on the plane of the sky would suggest. This result solves the long-standing mystery of why these two clouds form stars at different rates.
source https://www.lifetechnology.com/blogs/life-technology-science-news/3d-reconstruction-reveals-star-formation-activities-of-two-dust-clouds
