Astronomers have just assembled one of the most comprehensive portraits yet of the universe’s evolutionary history, based on a broad spectrum of observations by the Hubble Space Telescope and other space and ground-based telescopes. Each of the approximately 15,000 specks and spirals are galaxies, widely distributed in time and space. (NASA, ESA, P. Oesch of the University of Geneva, and M. Montes of the University of New South Wales)
Here’s an image to fire your imagination: Fifteen thousand galaxies in one picture — sources of light detectable today that were generated as much as 11 billion years ago.
Of those 15,000 galaxies, some 12,000 are inferred to be in the process of forming stars. That’s hardly surprising because the period around 11 billions years ago has been determined to be the prime star-forming period in the history of the universe. That means for the oldest galaxies in the image, we’re seeing light that left its galaxy but three billion years after the Big Bang.
This photo mosaic, put together from images taken by the Hubble Space Telescope and other space and ground-based telescopes, does not capture the earliest galaxies detected. That designation belongs to a galaxy found in 2016 that ...