NASA set to launch SPHEREx space telescope to scan entire sky

NASA’s newest space telescope will scan the entire sky in a range of near-infrared wavelengths to help astronomers better understand the evolution of the universe and search for promising spots for extraterrestrial life

By Matthew Sparkes

28 February 2025

Artist’s impression of the SPHEREx space telescope

NASA/JPL-Caltech

The latest addition to NASA’s fleet of space telescopes will launch this weekend and quickly set to work scanning the entire sky in a range of near-infrared wavelengths, collecting rich data on more than 450 million galaxies.

The Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx) is due to launch on 2 March atop a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California at 10.09pm local time.

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It carries a camera with a filter that splits incoming light like a prism and beams different portions of the spectrum onto 102 separate colour sensors. As the telescope pans around the sky, it slowly pieces together a complete image pixel by pixel. This strategy allows a relatively small and simple camera with no moving parts to do what might otherwise require a heavy and costly suite of sensors.

“If you scan the sky slowly by moving the telescope incrementally, then after enough time, every pixel in the sky will have been observed over a very wide wavelength range, giving you a crude spectrum of every bit of the sky, which has never been done before,” says Richard Ellis at University College London. “It’s a very small space telescope, but it’s got some very unique features.”

Ellis says this rich dataset will allow serendipitous discoveries. “It’s likely to find the unexpected,” he says.