NASA has just given the green light to a mission that will study many epochs of space history, from the earliest moments of a second after the big bang to today's planetary formation. The Space Spectrophotometer, the Age of Reionization, and the Ices Explorer (SPHEREx) will map the whole sky in the infrared wavelengths that are mostly blocked by the Earth's atmosphere.
"This is a great time," says SPHEREx chief researcher James Bock, an astronomer at the California Institute of Technology in Pasadena, who says he is happy to be just one member of a big team. "If only I was, I would really panic.
SPHEREx defeated another finalist in the middle class NASA (MIDEX), the mission's competitive line, whose costs are limited to $ 250 million. MIDEX's previous missions include the Expansion Monitor (TESS), which launched last year. SPHEREx received $ 242 million and is expected to start in 2023.
One of the main goals of SPHEREx will be to determine the distance from the Earth to 300 million galaxies and to map their 3D structure. Considering the over-density and insufficient density in their large-scale distribution, the mission may be able to annoy small effects from a hypothetical period in the early universe, known as inflation, when the universe expands exponentially in size in the moments after the big bang.
The initial quantum-mechanical fluctuations of the newborn universe, boosted by inflation, leave waves on the cosmic microwave background, the farthest light the telescopes can see. Similarly, inflation could generate a signature on galactic distribution, which would give researchers details of its details. Some theories suggest that energy for inflation comes from an associated particle field known as inflaton.
"It is possible that this opinion is simple," says Bock. "There are reasons to believe there will be many flights."
SPHEREx will also collect information about the general light emanating from the galaxies, giving insights into a poorly-researched epoch, known as reionization, when the first stars began to illuminate the universe and heat hydrogen clouds. Finally, closer to home, the mission will outline the abundance of ice in the molecular clouds in the Milky Way. When these clouds collapse, they form stars and planets, although the details of the process are not yet well known.
"Ice on the grains can be important for the build-up," says Bock. "For example, causing things to behave better."
In the MIDEX competition, SPHEREx wins over Arcus, which would explore X-ray galaxies to better understand supermassive black holes in their centers. The mission of the exoplanets, the rapid exploration of the exoplanets spectroscopy (FINESSE), was initially another finalist. But NASA has asked its designers to bring technology and expertise to a similar observatory developed by the European Space Agency, called Exoplanet Large (ARIEL).