SPHEREx: NASA’s New Eye on the Cosmos Begins Mapping the Universe

NASA’s latest space observatory, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer, mercifully shortened to SPHEREx, has officially commenced its primary mission: creating an unprecedentedly detailed map of the entire universe. Following a thorough six-week calibration period after its launch in early March, the space-based telescope is now fully operational and embarking on its two-year scientific endeavor. This ambitious project seeks to unlock some of the deepest mysteries of the cosmos, from its earliest moments to the distribution of essential building blocks of life.

SPHEREx is uniquely designed to observe the entire celestial sphere, scanning the whole sky every six months. Unlike many telescopes that focus on specific areas, SPHEREx’s comprehensive approach will provide a holistic view of the universe, capturing a wealth of data that will enable scientists to address some of the most fundamental questions in cosmology. To achieve this vast undertaking, the spacecraft orbits the Earth approximately 14 times daily, each time capturing a new strip of the Milky Way and the cosmos beyond. This continuous scanning results in the acquisition of about 3,600 infrared images every single day.

The telescope’s strength lies in its ability to detect light at infrared wavelengths, a portion of the electromagnetic spectrum invisible to the human eye. This infrared radiation carries crucial information about cosmic objects and events that occurred far back in the universe’s history. By analyzing this light, scientists can peek into the universe’s past, tracing its evolution and gaining insights into its formation. SPHEREx is equipped with six detectors that meticulously split the incoming light into 102 distinct infrared colors. This process, known as spectroscopy, allows researchers to determine the composition and properties of distant objects. Over its lifespan, the mission anticipates making over 9 million observations of interstellar clouds within our own galaxy.

The scientific objectives of SPHEREx are ambitious and wide-ranging. One of the primary goals is to investigate the period of cosmic inflation, an era when the universe expanded at an exponential rate in the fractions of a second after the Big Bang. Although incredibly brief, this period of inflation is believed to have had a profound effect on the structure of the universe we observe today. SPHEREx will search for subtle patterns in the distribution of galaxies across the sky, which could serve as fingerprints of this primordial expansion. By studying these patterns, scientists hope to gain a better understanding of the physical processes that governed the universe’s earliest moments.

Jim Fanson, the mission’s project manager at NASA’s Jet Propulsion Laboratory, highlights the unique approach of SPHEREx, stating that "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." This perspective emphasizes the profound connection between the universe’s infancy and its present state. By observing the large-scale structure of the cosmos, SPHEREx aims to shed light on the minute, quantum fluctuations that occurred during inflation and seeded the formation of galaxies and other cosmic structures.

Beyond its investigation of cosmic inflation, SPHEREx will also delve into the chemical composition of the universe. By using spectroscopy, the mission will analyze the light from distant galaxies, star-forming regions, and dusty clouds within the Milky Way. This analysis will reveal the abundance of various elements and molecules, including those crucial for life, such as water and organic compounds. By mapping the distribution of these essential ingredients throughout the universe, SPHEREx will contribute to our understanding of how life arose and spread across the cosmos.

The data collected by SPHEREx will be invaluable in mapping the distribution of water in star-forming regions. Water is critical for the formation of planets, so locating where it exists in space is of utmost importance. SPHEREx will be able to detect frozen water in molecular clouds and protoplanetary disks. By mapping the distribution of organic molecules in space, researchers can work to further understanding of the origin of life.

Jamie Bock, the principal investigator for the SPHEREx mission, expressed his enthusiasm for the observatory’s performance, noting that "The performance of the instrument is as good as we hoped." This indicates that the telescope is operating at its full potential and is capable of achieving its ambitious scientific goals. Bock added that the team expects to make many amazing scientific discoveries and some discoveries that weren’t anticipated.

Over the course of its two-year mission, SPHEREx is expected to capture hundreds of thousands of images, which will then be meticulously assembled into four all-sky maps. These maps will be a treasure trove of information for astronomers and cosmologists, providing a comprehensive view of the universe at infrared wavelengths. The data from SPHEREx will be used to study a wide range of phenomena, from the formation of stars and galaxies to the distribution of dark matter. The resulting maps will serve as a valuable resource for the scientific community, enabling researchers to explore the origins and evolution of the universe in unprecedented detail.

SPHEREx will be the first mission to map the entire sky in so many colors. The all-sky survey will enable researchers to understand how galaxies are formed and where they’re located in space. With the data from the mission, scientists can better understand the physics of the Big Bang, and the role that dark matter plays in the evolution of the universe. SPHEREx is a critical component to space-based research, and it will serve as an important mission in our understanding of the origins of the universe.

In summary, SPHEREx represents a significant step forward in our quest to understand the universe. With its ability to map the entire sky in multiple infrared colors, the mission will provide a wealth of data that will help scientists address some of the most fundamental questions in cosmology. From probing the mysteries of cosmic inflation to charting the distribution of essential ingredients for life, SPHEREx is poised to make groundbreaking discoveries and reshape our understanding of the cosmos.