Astronomers and engineers have designed telescopes, in part, to be “time travelers.” The farther away an object is, the longer its light takes to reach Earth. Peering back in time is one reason why NASA’s upcoming James Webb Space Telescope specializes in collecting infrared light: These longer wavelengths, which were initially emitted by stars and galaxies as ultraviolet light more than 13 billion years ago, have stretched, or redshifted, into infrared light as they traveled toward us through the expanding universe.
Although many other observatories, including NASA’s Hubble Space Telescope, have previously created “deep fields” by staring at small areas of the sky for significant chunks of time, the Cosmic Evolution Early Release Science (CEERS) Survey, led by Steven L. Finkelstein of the University of Texas at Austin, will be one of the first for Webb. He and his research team will spend just over 60 hours pointing the telescope at a slice of the sky known as the Extended Groth Strip, which was observed as part of Hubble’s Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey or CANDELS.
“With Webb, we want to do the first reconnaissance for galaxies even closer to the big bang,” Finkelstein said. “It is absolutely not possible to do this research with any other telescope. Webb is able to do remarkable things at wavelengths that have been difficult to observe in the past, on the ground or in space.”
Mark Dickinson of the National Science Foundation’s National Optical-Infrared Astronomy Research Laboratory in Arizona, and one of the CEERS Survey co-investigators, gives a nod to Hubble while also looking forward to Webb’s observations. “Surveys like the Hubble Deep Field have allowed us to map the history of cosmic star formation in galaxies within a half a billion years of the big bang all the way to the present in surprising detail,” he said. “With CEERS, Webb will look even farther to add new data to those surveys.”
Source: “Mapping the Early Universe with NASA’s Webb Telescope” NASA, 24 June 2020. <https://www.nasa.gov/feature/goddard/2020/mapping-the-early-universe-with-nasas-webb-telescope>