A demonstration figure of interstellar dust and China's Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST). /China Media Group

Chinese and foreign astronomers have unveiled the first 3D map of the properties of interstellar dust in the Milky Way. This breakthrough will provide critical support for precise astronomical observations and studies in astrochemistry and galactic evolution.

The research was led by Zhang Xiangyu, a Chinese doctoral student at Germany's Max Planck Institute for Astronomy, in collaboration with his advisor, Gregory Green. It was based on data from China's Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and the European Space Agency's Gaia space observatory. The findings were published as the cover story of the latest issue of the Science academic journal.

The interstellar medium – the matter and radiation in the space between stars – plays a key role in the Milky Way's material cycle and star formation. Most elements heavier than hydrogen and helium in the interstellar medium exist as solid dust particles. Dust absorbs and scatters starlight, making distant stars appear dimmer and redder in a phenomenon known as "extinction." Most astronomical observations require extinction correction.

By integrating precise stellar parameters from LAMOST with low-resolution spectroscopic survey data from Gaia, astronomers compiled the first comprehensive catalog detailing the absorption and scattering from interstellar dust for over 130 million stars. Using this catalog, they successfully constructed a 3D map of dust distribution and properties across the Milky Way, reaching distances of up to 16,308 light-years away.