SPHEREx, NASA’s new space telescope, just opened its eyes to the universe and delivered its very first images from space. Though not yet fully calibrated, the images already showcase a sweeping view filled with stars and galaxies — over 100,000 sources in each frame.
SPHEREx detects invisible infrared light and splits it into 102 hues to reveal secrets about the origins of water, galaxy distances, and even the physics of the early universe. With all systems working and its ultra-chilled detectors focused and functional, the mission promises to revolutionize cosmic surveys by mapping the entire sky multiple times and complementing more focused telescopes like Hubble and Webb.
SPHEREx Comes Alive in Space
NASA’s SPHEREx (short for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) has switched on its detectors in space for the very first time. The initial images, captured after the observatory’s March 11 launch, confirm that all systems are functioning as expected.
While these early images are still uncalibrated and not yet ready for scientific analysis, they offer an exciting preview of SPHEREx’s incredibly wide view of the sky. Each bright point in the images represents a light source, such as a star or galaxy, and each image is expected to contain over 100,000 detected sources.
A Massive Field of View
Every SPHEREx exposure includes six images, one from each of its detectors. The top three and bottom three images show overlapping areas of the sky, revealing the observatory’s full field of view, a rectangular swath of space roughly 20 times wider than the full Moon. Once routine science operations begin in late April, SPHEREx will capture about 600 exposures per day.
“Our spacecraft has opened its eyes on the universe,” said Olivier Doré, SPHEREx project scientist at Caltech and NASA’s Jet Propulsion Laboratory, both in Southern California. “It’s performing just as it was designed to.”
Turning Infrared into Insight
The SPHEREx observatory detects infrared light, which is invisible to the human eye. To make these first images, science team members assigned a visible color to every infrared wavelength captured by the observatory. Each of the six SPHEREx detectors has 17 unique wavelength bands, for a total of 102 hues in every six-image exposure.
Breaking down color this way can reveal the composition of an object or the distance to a galaxy. With that data, scientists can study topics ranging from the physics that governed the universe less than a second after its birth to the origins of water in our galaxy.
“This is the high point of spacecraft checkout; it’s the thing we wait for,” said Beth Fabinsky, SPHEREx deputy project manager at JPL. “There’s still work to do, but this is the big payoff. And wow! Just wow!”
Chilling Out for Infrared Clarity
During the past two weeks, scientists and engineers at JPL, which manages the mission for NASA, have executed a series of spacecraft checks that show all is well so far. In addition, SPHEREx’s detectors and other hardware have been cooling down to their final temperature of around minus 350 degrees Fahrenheit (about minus 210 degrees Celsius). This is necessary because heat can overwhelm the telescope’s ability to detect infrared light, which is sometimes called heat radiation. The new images also show that the telescope is focused correctly. Focusing is done entirely before launch and cannot be adjusted in space.
“Based on the images we are seeing, we can now say that the instrument team nailed it,” said Jamie Bock, SPHEREx’s principal investigator at Caltech and JPL.
Broad Surveys, Big Discoveries
Where telescopes like NASA’s Hubble and James Webb space telescopes were designed to target small areas of space in detail, SPHEREx is a survey telescope and takes a broad view. Combining its results with those of targeted telescopes will give scientists a more robust understanding of our universe.
The observatory will map the entire celestial sky four times during its two-year prime mission. Using a technique called spectroscopy, SPHEREx will collect the light from hundreds of millions of stars and galaxies in more wavelengths than any other all-sky survey telescope.
How SPHEREx Sees in Color
When light enters SPHEREx’s telescope, it’s directed down two paths that each lead to a row of three detectors. The observatory’s detectors are like eyes, and set on top of them are color filters, which are like color-tinted glasses. While a standard color filter blocks all wavelengths but one, like yellow- or rose-tinted glasses, the SPHEREx filters are more like rainbow-tinted glasses: The wavelengths they block change gradually from the top of the filter to the bottom.
“I’m rendered speechless,” said Jim Fanson, SPHEREx project manager at JPL. “There was an incredible human effort to make this possible, and our engineering team did an amazing job getting us to this point.”
More About SPHEREx
SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) is a NASA mission designed to map the entire sky in infrared light, providing data on everything from the origins of water in the galaxy to the large-scale structure of the universe. Managed by NASA’s Jet Propulsion Laboratory (JPL) for the agency’s Astrophysics Division, SPHEREx is led by a principal investigator based at Caltech with a joint appointment at JPL.
The telescope and spacecraft bus were built by BAE Systems (formerly Ball Aerospace), while Caltech oversaw the integration of the instrument. A diverse team of scientists from 10 U.S. institutions, as well as teams in South Korea and Taiwan, will carry out the scientific analysis. All mission data will be processed and archived at IPAC at Caltech and made publicly available through the NASA-IPAC Infrared Science Archive. Caltech also manages JPL for NASA.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.