NASA’s Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) has made significant contributions to our understanding of the cosmos by capturing detailed data from more than 450 million galaxies and 100 million stars in the Milky Way. During its two-year mission, SPHEREx is conducting an all-sky survey to explore the origins and evolution of the Universe. Notably, the mission team recently turned its attention to the interstellar object 3I/ATLAS, enhancing our knowledge of this intriguing celestial body.
In December 2022, as 3I/ATLAS emerged from behind the Sun, SPHEREx utilized its advanced triple-mirror telescope to gather unique infrared (IR) data. This technology allows SPHEREx to observe the sky in 102 colors, each corresponding to a different infrared wavelength. Such capabilities are typically employed to analyze galaxies, stars, and planet-forming regions. However, in this instance, the focus was on the composition of 3I/ATLAS’s coma, the bright, gaseous envelope surrounding the object that forms as it approaches the Sun.
The observations revealed critical information about the chemical makeup of 3I/ATLAS. As it draws closer to the Sun, frozen volatiles like water and carbon dioxide sublimate, releasing dust and other materials from within the comet. SPHEREx’s IR images highlighted essential elements including water vapor, carbon dioxide, and organic molecules. This data is crucial for scientists seeking to understand how 3I/ATLAS interacts with solar heat and what compounds are locked within it.
The anticipation surrounding 3I/ATLAS intensified after it disappeared behind the Sun in late October 2022. Researchers were eager to observe its return, knowing that its closest approach would result in increased outgassing. This phenomenon not only provides insights into its current composition but also hints at its origin and the conditions of its home system.
SPHEREx, alongside other observational missions, is poised to gather further information on 3I/ATLAS while the object remains visible. The ongoing analysis will enhance our understanding of its journey through the Solar System and offer new perspectives on complex organic molecules (COMs) that may play a role in the development of life.
As SPHEREx continues its vital mission, the insights gained from 3I/ATLAS serve as a reminder of our Universe’s vastness and complexity. The data collected not only enriches our knowledge of this specific interstellar object but also contributes to the broader quest of understanding the fundamental processes that govern the cosmos.
