On March 12, 2025, NASA’s new observatory, SPHEREx, was launched into a sun-synchronous polar orbit around the Earth. It’s almost a “relative” of the James Webb telescope, since SPHEREx will operate in the near-infrared range. Moreover, the new observatory will simultaneously image the Universe at 102 infrared wavelengths, creating the most detailed infrared map of the Milky Way.
Artist’s rendering of SPHEREx. Image source: NASA
Until the end of April, and possibly longer, the SPHEREx observatory will be cooling its detectors, which will be able to capture light in the “thermal” infrared range. Each of the observatory’s six detectors is sensitive to 17 wavelengths; together, they record photons at 102 frequencies of light invisible to the human eye. The total width of the frame reaches 20 full moons. SPHEREx will create the first complete sky survey in the first six months of operation. In total, the observatory should operate for 25 months.
The SPHEREx observatory sent its first test images at the end of March. Their quality shows that the instruments are capable of focusing distant light, creating clear images. The catch is that the focus could only be adjusted in terrestrial conditions, and after the launch into space, engineers had to work with what they got – with no room for error. NASA says the result met expectations.
SPHEREx will also look for traces of water in the universe and organics in the form of a range of basic carbon compounds. It will also study the evolution of galaxies, collecting data on more than 450 million objects. By the end of April, SPHEREx is expected to be able to take up to 600 images of the sky per day. With its wide-angle camera, the instrument can help Webb find the most interesting targets.