By Martin Rees and Donald Goldsmith
July 21, 2022 12:01 PM ET
NASA’s release of stunning images from the James Webb Space Telescope marks the beginning of a new era of astronomical observation of space. With seven times more light-gathering power than its predecessor, the Hubble Telescope, Webb opens our eyes to the cosmos like never before and will give us new information about distant worlds, galaxy formation and the farthest reaches of the space But the Webb telescope also exemplifies a crucial practical point: It shows why robotic explorers are superior to human astronauts in advancing our understanding of the universe.
Consider the location of the new telescope in space. Hubble had to remain only 335 miles above Earth because NASA only had the space shuttle manned by astronauts to launch it; therefore, it suffered from interference from light reflected off the planet’s surface and from the obstruction of the Earth itself. It was as if astronomers had placed one of Hawaii’s powerful Keck telescopes amid the lights of New York City instead of a dark peak in the Pacific. The Webb array, by contrast, orbits in a dark, deep spot called “L2,” nearly a million miles beyond Earth, which it can do because it was launched by an unmanned rocket and is designed to stay put with the guide of the controllers of the Earth. but without practical human intervention. An unusually large grain of space dust damaged one of the telescope’s 18 mirrors in May, but this has so far not affected its overall operation.