Each telescope will point at Sagittarius A*, the supermassive black hole at the centre of the Milky Way, and measure every radio wave coming from its direction. Linking together observatories spread across such a huge area and combining their observations to filter out extra light will effectively create a powerful “virtual telescope” almost the size of Earth.

Source: Earth-sized telescope set to snap first picture of a black hole | New Scientist

As other telescopes are added to the network in coming decades, observations of the black holes will become even more precise, and should provide fundamental insights into the workings of our universe.