Black holes are some of the most extreme objects in the universe, and a new mission proposal suggests launching a space telescope specifically to study them. The Event Horizon Telescope (EHT) group, which took both the first-ever image of a black hole in 2019 and the first-ever image of the supermassive black hole at the center of our galaxy in 2022, has plans for a new mission called the Black Hole Explorer (BHEX).
The idea of BHEX is to use a space-based telescope to collect even more detailed information from black holes, as there is less interference from water vapor when viewing them from above the Earth’s atmosphere. The aim would be to combine data from this telescope with the many telescopes on the ground that are already used in the EHT project. The next phase of the project is a collaboration between the Center for Astrophysics | Harvard & Smithsonian (CfA) and the National Radio Astronomy Observatory (NRAO).
“This collaboration with NRAO marks a significant step forward in our quest to understand the nature of black holes,” said Michael Johnson, principal investigator for BHEX at the CfA. “By extending the EHT to space, we’ll be able to study dozens of black holes and see how they power the brightest engines in the universe.”
The CfA team is preparing a proposal for the BHEX mission to be submitted to NASA next year, with the aim of a 2031 launch. Like previous work of the Event Horizon Telescope project, it aims to view details from around the supermassive black holes that lie at the center of almost all galaxies.
Though black holes themselves are invisible because they are so dense that not even light can escape them, the area immediately around a black hole’s event horizon can be busy and chaotic. Often, there are large amounts of dust and gas swirling around a black hole, attracted and accelerated by its extreme gravity. As this material rubs together, it becomes hot and starts to glow — and for large and active black holes, this glow can even be seen and studied from Earth.
When launching a space-based telescope, the ground infrastructure is an important part of the mission — there needs to be facilities to download and transmit data from space, as well as collect data directly from the ground. NRAO is part of facilities like the Green Bank Telescope and the Atacama Large Millimeter/submillimeter Array (ALMA) which could be used to relay data from the proposed space telescope.
“NRAO leads and operates some of the most sensitive radio observatories in the world, making for a perfect partnership with the CfA to make this hybrid radio observatory happen,” said Sara Issaoun, a Submillimeter Array Fellow at the CfA and the BHEX science operations lead. “By combining space-based and ground-based observations, we’ll be able to achieve unprecedented resolution and gain new insights into these cosmic phenomena.”
