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 was 420 million years old at the time it sent out the photons just collected. (Photo below.)
Nor is it quite as visually dramatic as the iconic Ultra Deep Field image produced by NASA in 2014. (Photo below as well.)
But this image is one of the most comprehensive yet of the history of the evolution of the universe, presenting galaxy light coming to us over a timeline up to those 11 billion years. The image was released last week by NASA and supports an earlier paper in The Astrophysical Journal by Pascal Oesch of Geneva University and a large team of others.
And it shows, yet again, the incomprehensible vastness of the forest in which we are a tiny leaf.
Some people apparently find our physical insignificance in the universe to be unsettling. I find it mind-opening and thrilling — that we now have the capability to not only speculate about our place in this enormity, but to begin to understand it as well.
The Ultra-Deep field composite, which contains approximately 10,000 galaxies. The images were collected over a nine-year period. {
