An instrument designed to observe the vast skeins of gas that connect galaxies will soon be installed at the Keck Observatory on Mauna Kea.

Caltech physics professor Christopher Martin, the leader of the Keck Cosmic Web Imager team, said one of its main goals will be to determine what that gas is doing.

“For decades, astronomers have demonstrated that galaxies evolve. Now we’re trying to figure out how and why,” Martin said in a statement. “We know the gas around galaxies is ultimately fueling them, but it is so faint — we still haven’t been able to get a close look at it and understand how this process works.”

Using a precursor instrument at the Palomar Observatory near San Diego, Martin and colleagues recently confirmed what is known as the “cold flow” model, in which gas funnels into the cores of galaxies, where it condenses and forms new stars.