NASA’s SPHEREx observatory, launched on March 11, 2025, has activated its detectors and delivered its first images from space, confirming that the spacecraft is functioning as intended. Processed with rainbow hues to represent various infrared wavelengths, these initial, uncalibrated pictures offer a glimpse of the universe through the Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer. The images, released on April 3, 2025, mark a key milestone as the mission prepares for science operations later this month.
Each exposure from SPHEREx includes six images—one per detector—covering a rectangular field of view 20 times wider than the full Moon. The top three images mirror the bottom three, showcasing the observatory’s broad perspective. Scientists estimate each image contains over 100,000 light sources, such as stars and galaxies.
“Our spacecraft has opened its eyes on the universe,” said Olivier Doré, SPHEREx project scientist at Caltech and NASA’s Jet Propulsion Laboratory (JPL). “It’s performing just as it was designed to.” Routine operations, set to begin in late April, will involve approximately 600 daily exposures.
SPHEREx detects infrared light, invisible to humans, and assigns visible colors to its 102 wavelength bands—17 per detector—across the six-image sets. This spectroscopy technique will allow researchers to analyze object compositions and galaxy distances, aiding studies on the universe’s early physics and the origins of water in our galaxy. The observatory, cooled to minus 350 degrees Fahrenheit (minus 210 degrees Celsius) to minimize heat interference, has also demonstrated proper focus, set before launch. “Based on the images we are seeing, we can now say that the instrument team nailed it,” said Jamie Bock, principal investigator at Caltech and JPL.
Over the past two weeks, JPL engineers completed spacecraft checks, verifying detector performance and hardware stability. “This is the high point of spacecraft checkout; it’s the thing we wait for,” said Beth Fabinsky, deputy project manager at JPL. “There’s still work to do, but this is the bigInfrared payoff.” Unlike the detailed views of Hubble and James Webb, SPHEREx surveys vast sky areas, complementing targeted telescopes. It will map the entire sky four times in its two-year mission, collecting data on hundreds of millions of celestial objects.
The mission, managed by JPL for NASA’s Astrophysics Division, features a telescope and spacecraft bus built by BAE Systems. Data analysis involves scientists from 10 U.S. institutions, two in South Korea, and one in Taiwan, with Caltech handling science operations and archiving at IPAC. “I’m rendered speechless,” said Jim Fanson, project manager at JPL. “There was an incredible human effort to make this possible.” The public can track SPHEREx via NASA’s Eyes on the Solar System and access its dataset at the NASA-IPAC Infrared Science Archive. More details are available at https://science.nasa.gov/mission/spherex/.
