Black holes are awe-inspiring objects that are still not well understood despite the amount of research dedicated to them. Researchers at MIT, the Harvard-Smithsonian Center for Astrophysics and other institutions have linked multiple telescopes across the planet to create the Event Horizon Telescope (EHT) which can capture details 2000 times finer than the Hubble Space Telescope. They aimed this array at the heart of the galaxy M87 and its 6 billion solar-mass black hole. What they found could determine how the jets emanating from black holes form.
Orbiting many black holes are accretion disks that reach as close to the black hole as matter can get, without falling in. Also at many black holes are massive jets that launch matter hundreds of thousands of light years away from the black hole at very high speed. Exactly what powers these jets has been a matter of debate for some time, but the EHT and its observations may finally explain if it is the black hole's spin itself that powers the jets or energy from the nearest edge of the accretion disk. Among these observations is a measure of the nearest stable orbit matter can have before being doomed to fall into the black hole; roughly 5.5 times larger than the size of the event horizon from which light cannot escape.
As more observations are made and new details not before observable are discovered, theories, including General Relativity, can be tested against reality and either validated or rejected. To help with this, the researchers are looking to add even more radio telescopes to the EHT, which will increases its power significantly.