NASA’s SPHEREx space observatory has kicked off its sky-mapping mission, capturing 3,600 images per day to unravel cosmic mysteries like the Big Bang and the building blocks of life.
Over two years, it will generate full-sky maps in 102 infrared colors, revealing everything from the 3D structure of galaxies to the chemical fingerprints of water in the Milky Way.
SPHEREx Begins Mapping the Entire Sky
Launched on March 11, NASA’s SPHEREx space observatory has spent the past six weeks undergoing careful checkouts and calibrations to confirm that all systems are functioning as intended. Now fully operational, SPHEREx has begun mapping the entire sky, not just a portion of it, to create a 3D map of hundreds of millions of galaxies. The mission aims to answer major questions about the origins of the universe, the evolution of galaxies, and the presence of life-supporting ingredients in our own Milky Way.
On May 1, the spacecraft entered its science operations phase, capturing around 3,600 infrared images per day. Over its planned two-year mission, these observations will provide groundbreaking insights into cosmic history and structure.
A New Era of Cosmic Cartography
“Thanks to the hard work of teams across NASA, industry, and academia that built this mission, SPHEREx is operating just as we’d expected and will produce maps of the full sky unlike any we’ve had before,” said Shawn Domagal-Goldman, acting director of the Astrophysics Division at NASA Headquarters in Washington. “This new observatory is adding to the suite of space-based astrophysics survey missions leading up to the launch of NASA’s Nancy Grace Roman Space Telescope. Together with these other missions, SPHEREx will play a key role in answering the big questions about the universe we tackle at NASA every day.”
Orbiting Earth to Chart the Cosmos
From its orbit around Earth, SPHEREx gazes into deep space, always pointing away from both the Sun and our planet. Over its 25-month mission, it will complete more than 11,000 orbits, circling the globe about 14½ times a day. SPHEREx follows a polar orbit, passing over Earth’s poles and imaging a circular strip of the sky each day. As Earth moves around the Sun, SPHEREx’s field of view gradually shifts, allowing it to scan the entire sky every six months.
How SPHEREx Captures the Sky
When SPHEREx takes a picture of the sky, the light is sent to six detectors that each produce a unique image capturing different wavelengths of light. These groups of six images are called an exposure, and SPHEREx takes about 600 exposures per day. When it’s done with one exposure, the whole observatory shifts position — the mirrors and detectors don’t move as they do on some other telescopes. Rather than using thrusters, SPHEREx relies on a system of reaction wheels, which spin inside the spacecraft to control its orientation.
Building a 3D Map of the Universe
Hundreds of thousands of SPHEREx’s images will be digitally woven together to create four all-sky maps in two years. By mapping the entire sky, the mission will provide new insights about what happened in the first fraction of a second after the Big Bang. In that brief instant, an event called cosmic inflation caused the universe to expand a trillion-trillionfold.
“We’re going to study what happened on the smallest size scales in the universe’s earliest moments by looking at the modern universe on the largest scales,” said Jim Fanson, the mission’s project manager at NASA’s Jet Propulsion Laboratory in Southern California. “I think there’s a poetic arc to that.”
This video shows the SPHEREx observatory’s field of view as it scans across one section of the sky inside the Large Magellanic Cloud, with rainbow colors representing the infrared wavelengths the telescope’s detectors see. The view from one detector array moves from purple to green, followed by the second array’s view, which changes from yellow to red. The images are looped four times. Credit: NASA/JPL-Caltech
Tracing Clues from the Big Bang
Cosmic inflation subtly influenced the distribution of matter in the universe, and clues about how such an event could happen are written into the positions of galaxies across the universe. When cosmic inflation began, the universe was smaller than the size of an atom, but the properties of that early universe were stretched out and influence what we see today. No other known event or process involves the amount of energy that would have been required to drive cosmic inflation, so studying it presents a unique opportunity to understand more deeply how our universe works.
“Some of us have been working toward this goal for 12 years,” said Jamie Bock, the mission’s principal investigator at Caltech and JPL. “The performance of the instrument is as good as we hoped. That means we’re going to be able to do all the amazing science we planned on and perhaps even get some unexpected discoveries.”
Seeing the Universe in 102 Colors
The SPHEREx observatory won’t be the first to map the entire sky, but it will be the first to do so in so many colors. It observes 102 wavelengths, or colors, of infrared light, which are undetectable to the human eye. Through a technique called spectroscopy, the telescope separates the light into wavelengths — much like a prism creates a rainbow from sunlight — revealing all kinds of information about cosmic sources.
For example, spectroscopy can be harnessed to determine the distance to a faraway galaxy, information that can be used to turn a 2D map of those galaxies into a 3D one. The technique will also enable the mission to measure the collective glow from all the galaxies that ever existed and see how that glow has changed over cosmic time.
And spectroscopy can reveal the composition of objects. Using this capability, the mission is searching for water and other key ingredients for life in these systems in our galaxy. It’s thought that the water in Earth’s oceans originated as frozen water molecules attached to dust in the interstellar cloud where the Sun formed.
The SPHEREx mission will make over 9 million observations of interstellar clouds in the Milky Way, mapping these materials across the galaxy and helping scientists understand how different conditions can affect the chemistry that produced many of the compounds found on Earth today.
More About SPHEREx
SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) is a NASA mission mapping the entire sky in infrared light to explore the origins of the universe, galaxy formation, and the ingredients for life. Managed by NASA’s Jet Propulsion Laboratory (JPL) for the Astrophysics Division, the mission was developed with major contributions from Caltech, which integrated the instrument and hosts the principal investigator.
The spacecraft and telescope were built by BAE Systems in Boulder, Colorado. A global science team — spanning 10 U.S. institutions, two in South Korea, and one in Taiwan — will analyze the data. All observations will be processed and archived by IPAC at Caltech and made publicly available through the NASA-IPAC Infrared Science Archive.
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
1 Comment
The answer to your origins question is already available: On the 4th day of Creation Week God created the greater light to rule the day and the lesser light to rule the night, and the stars,too. No bang,just their appearance at His command.