Nasa's newest space telescope rocketed off on March 11, 2025, from Vandenberg Space Force Base in Lompoc, California. The SPHEREx telescope, short for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer, aims to map the entire sky and explore the origins of the universe through groundbreaking cosmic observations.
Launched aboard SpaceX's Falcon 9 rocket, the SPHEREx mission boasts a budget of $488 million and is anticipated to significantly deepen our comprehension of cosmic phenomena. Over its two-year mission, the telescope will collect data from more than 450 million galaxies and more than 100 million stars within our Milky Way. This ambitious venture will create the first three-dimensional map of the cosmos, utilizing 102 colors, or individual wavelengths of light, to achieve its aims.
The mission's primary objective is to probe the mystery of cosmic inflation, which describes the rapid expansion of the universe from nearly nothing to its vast current state following the Big Bang, 13.8 billion years ago. The phenomenon, as explained by Phil Korngut, instrument scientist at Caltech, suggests the universe expanded trillions of times its size within just moments, forming the large-scale structures we see today.
SPHEREx is uniquely equipped with advanced infrared detectors, which can distinguish 102 colors invisible to the human eye. These capabilities will help scientists compile data about the collective light emitted by galaxies throughout cosmic history. “This cosmological glow captures all light emitted over cosmic history,” remarked Jamie Bock, the chief scientist for SPHEREx at Caltech. "It's a very different way of looking at the universe," he added, emphasizing the innovative approach of observing aggregated light to reveal previously elusive details about galaxy formation.
While SPHEREx will not focus on individual galaxies like its predecessors—the famed Hubble and Webb telescopes—it will provide insight by observing the combined light from galaxies, including the earliest ones formed after the Big Bang. Such observations may yield answers to long-standing questions about the emergence of these cosmic masses.
To operate efficiently, the telescope must remain at an extremely low temperature of minus-350 degrees Fahrenheit, necessitating its unique design. The SPHEREx’s structure, which resembles three aluminum honeycomb cones nesting within one another, acts as insulation against heat from the sun and Earth, akin to a 10-foot protective shield.
Alongside SPHEREx, four suitcase-sized satellites known as PUNCH were launched to investigate the sun's corona—the outer atmosphere—and its interactions with solar winds. This complementary mission aims to explore how solar phenomena influence Earth and the surrounding solar system. Nicholeen Viall, PUNCH mission scientist at NASA, emphasized the importance of integrating data from these satellites: “Together, they piece together the three-dimensional global view of the solar corona as it turns to solar wind, which fills our whole solar system.”
The origin of water on our planet is another aspect SPHEREx will target. Within the Milky Way, it will seek frozen reservoirs of water locked within dust grains found throughout large clouds of gas and dust. These molecular clouds are believed to be the primary breeding grounds for new stars and planets. The telescope will study water molecules and substances like carbon dioxide and carbon monoxide, helping scientists understand where much of the universe's water might form and exist.
The launch was originally scheduled for earlier but faced delays attributed to issues with the rocket. The successful liftoff signified not only technological advancements but also the potential for major discoveries about our universe.
SPHEREx's exploration of cosmic phenomena, alongside PUNCH's investigation of solar activity, aims to expand our knowledge of the cosmos, paving the way for future missions to understand our very existence. Shawn Domagal-Goldman, acting director of the Astrophysics Division at NASA headquarters, offered insight: “SPHEREx is going to search for reverberations from the Big Bang—the fractions of a second after the Big Bang.”
With its newly acquired data, scientists hope to improve the existing models of galaxy formation and evolution, providing unprecedented views of both our universe's origins and its lasting impacts.