Scientists can now study the event horizons of black holes
A new technique using high-resolution imaging has allowed scientists to directly observe and study the event horizons of black holes for the first time, offering unprecedented insights into the behavior of matter and gravity at the edge of these cosmic objects.
Background
- An **event horizon** is the boundary around a black hole beyond which nothing — not even light — can escape. Until recently, astronomers could only infer black holes indirectly or image their outer halos, but could not directly observe the edge itself.
- The **Event Horizon Telescope (EHT)** is a global network of radio observatories that works as a single Earth-sized telescope. In 2019 it produced the first-ever image of a black hole's shadow (M87*), and in 2022 the first image of Sagittarius A*, the black hole at the center of the Milky Way.
- This article reports on a new observational capability — likely an advance in interferometry, higher-frequency imaging, or space-based telescopes — that allows scientists to study the event horizon directly, not just the shadow or accretion disk. This means testing general relativity in the strongest possible gravitational fields and probing the "information paradox" (what happens to matter and information that falls in).