NASA’s SPHEREx space telescope, a collaboration with South Korea, unveiled its first images of the cosmos after capturing them on March 27. The images, assembled from six exposures covering an area roughly equivalent to 150 full moons, showed tens of thousands of celestial objects—including stars in the Milky Way and galaxies beyond.
Launched on March 11, aboard a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California, SPHEREx entered a 37‑day operational phase during which all tests and calibrations completed successfully. The telescope began mapping a vast portion of the sky, capturing about 600 images per day, with each image displaying up to 100,000 objects.
The images displayed differences in hue that provided a preview of the mission’s scientific capabilities. Short infrared wavelengths appeared in shades ranging from purple to blue, while longer wavelengths appeared in green to red. A bright line at the top of the first image resulted from helium in Earth’s atmosphere. Enlarged views in the green and blue boxes offered additional detail; the green box showed nearby galaxies, while the blue‑bordered box confirmed that the telescope could observe dark, distant galaxies.
SPHEREx was designed to capture the universe in 102 infrared wavelengths using its six detectors, which spanned 17 infrared bands. By surveying the sky in multiple colors, the telescope allowed scientists to study the composition of cosmic regions and determine distances to galaxies. Unlike telescopes such as Hubble and James Webb, SPHEREx offered a wider view through its infrared imaging spectroscopy, which enabled its data to be combined with that from other observatories. The design cooled the infrared optics and detectors to –210 degrees Celsius to prevent interference from the telescope’s own heat radiation while observing infrared signals.
Orbiting Earth in a polar trajectory, SPHEREx completed roughly 14.5 orbits per day and an estimated 11,000 orbits over its lifetime. It was expected to collect data on more than 450 million galaxies and over 100 million stars in the Milky Way, thereby creating a catalog of celestial objects. The data provided insight into fundamental questions in cosmology, including the physics of the universe, the origins of water in our galaxy, the record of galaxy evolution, and clues to the period of rapid inflation that followed the Big Bang. It was also expected to identify regions for further study with the James Webb Space Telescope.
Project scientists and managers expressed enthusiasm and optimism about the program. “Our spacecraft has opened its eyes on the universe. It performed as it was designed to,” said Olivier Doré, project scientist at Caltech and NASA’s Jet Propulsion Laboratory, according to a report by CBS News. “This is the high point of spacecraft checkout; it was the moment we awaited. Although work remained, the results were rewarding. And wow! Just wow!” said Beth Fabinsky, deputy project manager at JPL, according to a report by Yahoo News. “SPHEREx operated much better than expected. Using the data, we expected to conduct interesting research and both Korean and American teams were encouraged,” said Jeong Woong-seop, lead researcher at the Korea Astronomy and Space Science Institute, according to Hankyoreh.
The collaboration behind SPHEREx demonstrated international scientific partnership. The Korea Aerospace Research Institute, along with the Korea Astronomy and Space Science Institute and Caltech, worked together on the space mission, which cost $488 million to build and launch after a decade of development. “The successful observations of the SPHEREx space telescope meant a new beginning for space exploration,” said Yoon Young-bin, head of the Korea Aerospace Research Institute, according to Segye. “I hoped that through this, the research level of Korean scientists and Korea’s status would be further elevated,” he added.
The article was written with the assistance of a news analysis system.