Free Astronomy Magazine November-December 2024

NOVEMBER-DECEMBER 2024 Alexander Raymond, previously a postdoctoral scholar at the Center for Astrophysics | Harvard & Smith- sonian (CfA), and now at the Jet Propulsion Laboratory, both in the United States. “At 0.87 mm, our im- ages will be sharper and more de- tailed, which in turn will likely T his artist’s impression shows the locations of multiple radio observatories across the planet, which participated in a pilot experiment conducted by the Event Horizon Telescope (EHT) Collaboration that obtained the highest-resolution observa- tions from the ground. The test observations detected light from distant galaxies at a wavelength of 0.87 mm and were made with some of the observatories (in red) that are part of the EHT, a virtual Earth-sized telescope. One of these distant, point-like galaxies is represented on the top right, sending out radio signals all the way to Earth. [ESO/M. Kornmesser] T his animation video shows the locations of the radio observato- ries which participated in a pilot experiment conducted by the Event Horizon Telescope (EHT) Collaboration that obtained the high- est-resolution observa- tions from the ground. [ESO/M. Kornmesser] Earth, increasing the resolution of their ground-based observations called for a different approach. An- other way to increase the resolution of a telescope is to observe light of a shorter wavelength — and that’s what the EHT Collaboration has now done. “With the EHT, we saw the first im- ages of black holes using the 1.3- mm wavelength observations, but the bright ring we saw, formed by light bending in the black hole’s gravity, still looked blurry because we were at the absolute limits of how sharp we could make the images,” said the study’s co-lead