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The quest to locate water on distant celestial bodies is gaining momentum with NASA’s upcoming SPHEREx mission, poised to traverse the galaxy in search of potential ocean-forming compounds.
Water is essential for life as we know it, making it a focal point for astrobiologists exploring the potential for life beyond Earth. The SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer) mission, launching no earlier than February 27, aims to advance this search.
Lifted into space by a SpaceX Falcon 9 rocket from California’s Vandenberg Space Force Base, SPHEREx will scan for water, carbon dioxide, carbon monoxide, and other fundamental elements that may be encased in the icy structures of interstellar dust. These dust grains serve as the building blocks for stars and planets.
While the cosmos lacks free-floating oceans or lakes, scientists believe that vast reserves of ice embedded in minute dust grains are crucial reservoirs of water throughout the universe. Much of the water that populates the oceans of Earth and other celestial bodies likely originated from similar sources in these vast regions.
The mission will concentrate on extensive regions known as molecular clouds. Within these clouds, SPHEREx will investigate newly formed stars and the surrounding disks of material that are instrumental in planetary genesis.
Previous space telescopes, such as NASA’s James Webb and the retired Spitzer, have successfully detected various compounds, including water and carbon molecules. However, SPHEREx is uniquely positioned to perform a large-scale survey focused on finding water ice and other frozen materials.
Unlike traditional telescopes that capture two-dimensional images of stars, SPHEREx will acquire three-dimensional data along its observational path. This method allows scientists to ascertain the quantity of ice present in molecular clouds and to note how the composition of these ices varies across different conditions.
The mission aims to perform over 9 million observations, creating an expansive survey that will enhance understanding of how these essential compounds form on dust grains and how environmental conditions can affect their distribution.
This research addresses a fundamental question: how the materials constituting planets and stars relate back to the molecular clouds from which they emerged. Still, researchers often find that the universe can defy expectations. For example, a mission from 1998, the Submillimeter Wave Astronomy Satellite (SWAS), discovered significantly less gaseous water in molecular clouds than anticipated, prompting researchers to revise their theories about where water might actually be stored.
“This puzzled us for a while,” stated Gary Melnick, a senior astronomer at the Center for Astrophysics | Harvard & Smithsonian, and a member of the SPHEREx science team. “SWAS eventually revealed that gaseous water was present in limited areas near the surface of molecular clouds, implying that a larger reservoir of water ice might reside within their depths.”
Another aspect of this research is the interaction between oxygen and hydrogen in these clouds. As indicated by SWAS findings, reduced levels of gaseous oxygen suggested that oxygen atoms were adhering to interstellar dust grains and could combine with hydrogen to form water. Subsequent studies corroborated these findings, showing that molecular clouds effectively shield water ice and other compounds from cosmic radiation, preserving their integrity.
SPHEREx will employ absorption spectroscopy to analyze how light from stars is impacted as it passes through molecular clouds, allowing for the identification of water and carbon dioxide through their unique signatures.
In addition to mapping the quantity of these frozen compounds, SPHEREx will delve into essential questions such as the depth at which ice begins to form in molecular clouds, how the prevalence of water and other ices correlates with cloud density, and what variations occur post-stellar formation.
Designed as a survey telescope, SPHEREx will quickly analyze vast segments of the sky, providing complementary data that can be paired with findings from more focused telescopes like Webb. Webb can provide detailed observations of specific targets identified by SPHEREx.
“If SPHEREx identifies particularly compelling areas of interest, Webb can conduct in-depth studies with enhanced spectral detail,” explained Melnick. “Together, these telescopes represent a formidable collaborative approach.”
Managed by NASA’s Jet Propulsion Laboratory in Southern California, SPHEREx is a project of the Astrophysics Division of NASA’s Science Mission Directorate. BAE Systems built the telescope and spacecraft, while scientific analysis will be executed by teams at 10 U.S. institutions and a handful of collaborators in South Korea and Taiwan. Data from SPHEREx will be processed and made accessible at IPAC at Caltech, where NASA’s JPL also operates. The principal investigator for the mission is stationed at Caltech with a joint affiliation at JPL. Data derived from SPHEREx will eventually be available to the public through the NASA/IPAC Infrared Science Archive.
For further details on the SPHEREx mission, visit:
https://www.jpl.nasa.gov/missions/spherex/
Source
www.nasa.gov