The history of stars is written in the light of the countless galaxies in which they reside.
Staring long enough, at even a small patch of sky like Hubble’s Ultra Deep Field,
will reveal thousands of distant galaxies.
But the image of a galaxy tells only part of the story.
By spreading the galaxy’s light out into a spectrum, astronomers can learn about the ages of its stars,
its star formation history, and more.
The best way to get the whole story would be to reveal the spectra of every galaxy in an image, all at once.
NASA’s Roman Space Telescope has hardware designed to do just that.
Even better, its remarkably large field of view
can cover the area of a hundred Ultra Deep Fields in a single observation.
Such a bounty of galaxy spectra will help astronomers discover hidden chapters
in the universe’s history of stars.