Let it never be said that NASA doesn’t ask the big questions. Much of the press about space launches here in 2019 may come from private companies like Elon Musk’s SpaceX, but a forthcoming NASA mission promises one of the most ambitious space projects yet. It aims to launch a space observatory to create the most detailed ever map of the sky. In the process, it will survey hundreds of millions of galaxies — some of which are so far away that their light takes 10 billion years to reach Earth.
While the two-year, $242 million mission is still around five years from launching, it could help answer some fundamental questions about the universe. That mission statement is, literally, spelled out in its name: SPHEREx, an acronym of “Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer.”
“SPHEREx measures the spectrum of every point on the sky in a unique way,” Jamie Bock, SPHEREx’s principal investigator, told Digital Trends. “We place six linear variable filters over six detector arrays, located on the focal plane of a 20cm diameter telescope. Each filter passes a narrow range of wavelengths, but the center wavelength continuously shifts over the array.
“In a single exposure, we obtain a rainbow image, where each line of pixels in the image sees the sky at a different wavelength. To get a complete spectrum, we put together multiple exposures that we take over a period of several days. The advantage of this method is that the telescope covers wide swaths of sky in each image, which is necessary for covering the entire sky efficiently.”
Bock said that the project is intended to shed light on the beginning of the universe, the history of galaxy formation, and the role interstellar ices during the birth of new stars and planets. In the end, it will return four maps showing the entire sky. The spectral maps will be released so that they can be examined by the scientific community. Astronomers will then be able to use this to study everything from the solar system to distant galaxies.
“SPHEREx has now passed through a phase A study, which is a combination of modeling and paper calculations, with building and testing prototypes of a few key elements,” Bock continued. “With this announcement, we now get to go ahead and do a detailed design — and then build, test, and fly the instrument and spacecraft, make the observations, and analyze and release the data.”
And here we were thinking that Google’s Street View was impressively comprehensive.