Free Astronomy Magazine November-December 2024

28 NOVEMBER-DECEMBER 2024 ASTRO PUBLISHING These images were obtained by link- ing together multiple radio observa- tories across the planet, using a technique called very long baseline interferometry (VLBI), to form a sin- gle ‘Earth-sized’ virtual telescope. To get higher-resolution images, as- tronomers typically rely on bigger telescopes — or a larger separation between observatories working as part of an interferometer. But since the EHT was already the size of The highest-resolution observations yet from the surface of Earth T he EHT Collaboration released images of M87*, the super- massive black hole at the cen- tre of the M87 galaxy, in 2019, and of Sgr A*, the black hole at the heart of our Milky Way galaxy, in 2022. by ESO − Bárbara Ferreira