After a selection process of more than three years, NASA has selected a new mission among six projects in competition. It will be SPHEREx, a satellite whose launch is planned for 2023. The main objectives of this mission are to understand how everything started and where in our galaxy are the essential elements of life.
NASA has selected a new mission of study and observation of the sky. It is SPHEREx, an acronym for Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer. The objective of this satellite is ambitious: to study more than 300 million galaxies, some of which are more than 10 billion light-years away from Earth, and 100 million stars within the Milky Way. SPHEREx, which will be launched in 2023 for a lifetime of at least two years, has a budget of $ 242 million, excluding launch costs.
The idea is to draw up a new galactic census in terms of resolution and the number of colored bands. For this, the satellite will observe the entire sky to create global maps in 96 bands of different colors. The mass of data thus collected will be used to answer some fundamental questions that are plaguing astronomers and, in particular, to make a map of the distribution of the ingredients of life in the planetary systems of our galaxy.
How did the universe grow and where are the essentials for life?
To understand the evolution of the universe, astronomers, who have a pretty good idea of what happened a nanosecond or more after the Big Bang, are much more cautious about what happened before this nanosecond. Now, what we observe today is frozen in these first moments unknown to astronomers.
This is why SPHEREx aims to better understand the period of re-ionization where two major evolutions take place: these are the ionization of all the neutral gas, making the universe transparent, and the formation of the first stars and first structures containing these stars. This re-ionisation indicates the end of the dark age, a period that began some 380,000 years after the Big Bang and during which the universe does not contain stars.
As for the observation of the stars of the Milky Way, the data will be used to look for water and organic molecules, two elements essential to life as we know it, in stellar nurseries, regions where stars are born of gas and dust, as well as in disks around which new planets might form. This data will be used to identify habitable planetary systems that may be inhabited.
Finally, SPHEREx will also be used to identify targets of interest for future space missions including the James Webb Space Observatory.