Universe ID: 14297

How NASA's Roman Space Telescope Will Rewind the Universe

Released on March 1, 2023

In this simulated view of the deep cosmos, each dot represents a galaxy. The three small squares show Hubble's field of view, and each reveals a different region of the synthetic universe. Roman will be able to quickly survey an area as large as the whole zoomed-out image, which will give us a glimpse of the universe’s largest structures.

Credits: NASA’s Goddard Space Flight Center/A. Yung

A new simulation shows how NASA’s Nancy Grace Roman Space Telescope will turn back the cosmic clock, unveiling the evolving universe in ways that have never been possible before when it launches by May 2027. With its ability to rapidly image enormous swaths of space, Roman will help us understand how the universe transformed from a primordial sea of charged particles to the intricate network of vast cosmic structures we see today.

The simulation covers a two-square-degree patch of the sky, which is equivalent to about 10 times the apparent size of a full moon, containing over 5 million galaxies. It’s based on a well-tested galaxy formation model that represents our current understanding of how the universe works. Using an extremely efficient technique, the team can simulate tens of millions of galaxies in less than a day – something that could take years using conventional methods. When Roman launches and begins delivering real data, scientists can compare it to these simulations, putting their models to the ultimate test. That will help unravel galaxy formation physics, dark matter – a mysterious substance observed only through its gravitational effects – and much more.

In this side view of the simulated universe, each dot represents a galaxy whose size and brightness corresponds to its mass. Slices from different epochs illustrate how Roman will be able to view the universe across cosmic history. Astronomers will use such observations to piece together how cosmic evolution led to the web-like structure we see today.

Credits: NASA's Goddard Space Flight Center/A. Yung

This image, containing millions of simulated galaxies strewn across space and time, shows the areas Hubble (white) and Roman (yellow) can capture in a single snapshot. It would take Hubble about 85 years to map the entire region shown in the image, but Roman could do it in just 63 days. Roman’s larger view and fast survey speeds will unveil the evolving universe in ways that have never been possible before.

Credits: NASA's Goddard Space Flight Center/A. Yung

This simulated image covers two square degrees and contains millions of galaxies strewn across space and time. It’s based on a well-tested galaxy formation model that represents our current understanding of how the universe works.

Credits: NASA's Goddard Space Flight Center/A. Yung

This image is a slice from a simulated universe. Each dot represents a galaxy whose size and brightness corresponds to its mass. This slice represents the universe at a redshift of 6, which corresponds to 13 billion years ago.

Credits: NASA's Goddard Space Flight Center/A. Yung