NASA’s SPHEREx (Spectrophotometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) is an upcoming mission that promises to revolutionize how scientists explore the cosmos. Expected to launch no earlier than February 27, 2025, this state-of-the-art space telescope is poised to bring unprecedented insights into the workings of the universe.
SPHEREx, a project developed by NASA’s Jet Propulsion Laboratory, is distinct in its approach to surveying the cosmos. Unlike its predecessors, which often focus on specific sectors of the sky or prioritize detailed imagery, SPHEREx is designed to complete a full-sky scan in the infrared spectrum—something no astronomical mission has achieved to date. Here are six essential features and objectives of SPHEREx, outlining its significance and the reasons why it’s garnering global attention.
Firstly, SPHEREx aims to map the history of the universe’s expansion. Shortly after the Big Bang—a phase known as inflation—the universe exponentially expanded in an infinitesimal amount of time. To this day, scientists seek to understand the underlying mechanisms behind this phenomenon. By collecting data on galaxies’ distribution throughout cosmic history, SPHEREx will provide a comprehensive look at the large-scale structure of space-time and validate prevailing cosmological models.
Secondly, one of SPHEREx’s core objectives is to explore the so-called Epoch of Reionization, a period when the first galaxies began to emit light and ionize surrounding hydrogen. This period represents a vital chapter in cosmic history, as it marked the “lighting up” of the universe after millions of years of darkness. SPHEREx’s unprecedented infrared capabilities enable it to detect faint galaxy populations from this epoch, thereby aiding researchers in identifying the early building blocks of the cosmos.
The third significant aspect of SPHEREx lies in its ability to catalog molecular ices present in interstellar regions of our galaxy. Made up primarily of water, carbon, and other elements, these molecular ices are essential for life as we know it. These materials settle onto interstellar dust grains and form the foundations of planets and stars. By analyzing infrared light from these molecular ices, SPHEREx will help scientists decipher the chemical processes that lead to celestial formations, including conditions conducive to life.
Fourthly, SPHEREx complements other current and future NASA missions. While telescopes like Hubble and James Webb reveal deep but narrow views of space, SPHEREx provides the “big picture” by observing the entire celestial sphere in over 100 infrared wavelengths. This ability not only deepens the field of view but also points out areas that warrant closer scrutiny by their high-resolution imaging counterparts.
The fifth major highlight of SPHEREx is its technological uniqueness. Equipped with spectrophotometers, the telescope can divide light into various wavelengths equivalent to visual “fingerprints.” Each wavelength corresponds to different cosmic phenomena or elemental compositions. Capturing over 300 million spectra with remarkable efficiency, SPHEREx is expected to yield terabytes of data that will be critical for cross-referencing phenomena across wide swaths of the sky.
Lastly, SPHEREx’s role extends well beyond its immediate scientific goals. By continually monitoring cosmic phenomena with an all-sky mapping feature, it is likely to serendipitously discover new celestial bodies or rare events. This provides significant input to future exploratory missions both within and outside our solar system.
The SPHEREx mission is scheduled to launch from the Vandenberg Space Force Base in California, mounted aboard a SpaceX Falcon 9 rocket. Once operational, it will perform its surveys over a two-year interval, with each cycle generating a plethora of data, ripe for analysis and discovery. The data generated is entirely open-source, allowing scientists and astronomers worldwide to contribute to the mission’s analysis and expand upon its findings.
As SPHEREx prepares for lift-off, it joins the ranks of notable astronomical tools that enable humans to peer deep into the cosmos. Its contributions are expected to pave the way for years of investigative exploration, addressing unresolved questions about galaxy formation, cosmic evolution, and the intricacies of life’s building blocks.
