On Feb 13 NASA announced the selection of a new space mission that will help astronomers understand both how our universe evolved and how common are the ingredients for life in our galaxy’s planetary systems. The SPHEREx mission (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) is a planned two-year endeavor funded at $242 million (not including launch costs) and targeted to launch in 2023. SPHEREx will survey the sky in optical as well as near-infrared light and serve as a powerful tool for answering cosmic questions.
Astronomers will use the mission to gather data on more than 300 million galaxies, as well as more than 100 million stars in our own Milky Way. SPHEREx has three science goals: First, it will study the physics of the very early universe, a period known as “inflation”, during which the universe experienced a phase of extremely rapid expansion. Second, it will map the intensity of light emitted from galaxies across across cosmic time and thereby expand our knowledge on how galaxies form and evolve. Third, in the Milky Way, the mission will search for water and organic molecules – essentials for life, as we know it.
Every six months, SPHEREx will survey the entire sky using technologies adapted from Earth satellites and Mars spacecraft. The mission will create an all-sky map in 96 different color bands, far exceeding the color resolution of previous maps. It also will identify targets for more detailed study by future space missions and ground based surveys, such as the James Webb Space Telescope (JWST), the Wide Field Infrared Survey Telescope (WFIRST), the Large Synoptic Survey Telescope (LSST), and the Giant Magellan Telescope (GMT).
The mission’s principal investigator is James Bock of the California Institute of Technology (Caltech) in Pasadena, California. Steward Observatory’s Elisabeth Krause and Tim Eifler take part in the SPHEREx mission as members of the science team. Elisabeth is developing the modeling and inference framework to constrain the physics of inflation, Tim is exploring synergies between SPHEREx and LSST data to improve SPHEREx’s cosmological science return.
On Wednesday, NASA announced it had selected SPHEREx as the newest space telescope mission to investigate the early evolution of the universe and measure the prevalence of the ingredients for life within the Milky Way galaxy.
The University of Arizona’s Elisabeth Krause, assistant professor of astronomy and physics, is a mission co-investigator. UA assistant professor of astronomy and physics Tim Eifler is a mission collaborator.
The Spectro-Photometer for the History of the Universe, Epoch or Reionization and Ices Explorer is a two-year mission that is expected to launch in 2023 and is funded at $242 million, not including launch costs.
The California Institute of Technology in Pasadena will lead the science team, and the Jet Propulsion Laboratory will manage the mission.
“It’s a new window on the sky,” Krause said. From earth orbit, SPHEREx will survey the entire night sky every six months, gathering spectra — the separation of the components of light often seen as a rainbow — of more than 300 million galaxies to generate a map of galaxies near and far. Scientists like Krause hope to learn more about the expansion rate of the universe with this information.
Krause developed methods to estimate in advance how well SPHEREx will measure the inflation of the universe, she said. Astronomers want to understand what made the universe expand at physics-defying speeds during the fraction of a nanosecond after the big bang before giving rise to the myriad of galaxies and larger structure of the universe we observe today.
SPHEREx will also analyze over 100 million stars in the Milky Way and map water and organic molecules in our galaxy’s stellar nurseries and planet-forming regions.
The mission will also identify potential targets of study by future missions such as NASA’s UA-involved James Webb Space Telescope, Hubble Space Telescope’s successor.
This is all possible because of new technology that allows on-board instruments to produce the highest color resolution of all sky maps.
“It will take a spectrum of everything it detects,” Krause said. “And because we’ve never had such a satellite before, it allows a lot of science on many different fronts.”
Krause said she is excited the data garnered from this mission will be made public, allowing more discoveries than those outlined in the funding application.
For more information on the mission, go to spherex.caltech.edu.