Illustration of a wavy pink line connecting Earth to a distant galaxy across a dark grid, representing light traveling through space for the Roman Telescope Ultra Deep Field simulation.

How Far Into Space Can Telescopes See?

The Nancy Grace Roman Telescope has an even wider field of vision than Hubble.
NASA Goddard Space Flight Center
  • Encyclopædia Britannica, Inc.
    Many consider Brian May to be the greatest guitarist of all time. He's also an astrophysicist.
  • Encyclopædia Britannica, Inc.
    Learn more about solar eclipses, including their connection to Albert Einstein's general theory of relativity.
  • © Open University (A Britannica Publishing Partner)
    Overview of a plan for the Gaia satellite to take a “census” of stars, film 2013.
  • Astronomer Neil deGrasse Tyson exploring the question of whether the universe has a purpose.

Transcript

In 2004, NASA's Hubble Space Telescope changed astronomy forever when astronomers revealed the first ultra deep field image created with more than 270 hours of observation over the course of a year. It is our farthest ever visible light image of the universe. This tiny window revealed thousands of galaxies in a seemingly empty patch of sky. We can't see any farther invisible light, because the unrelenting expansion of space has stretched galaxies ultraviolet glow into red light.

More distant galaxies are mostly detectable in infrared. That's why in 2009, Hubble captured an infrared ultra deep field image that probed even deeper into the same spot. It remains one of the most distant images ever made, and a key source of information about some of the universe's early history.

The Nancy Grace Roman Space Telescope will have infrared resolution and capabilities similar to Hubble, but each image will cover 200 times the area of sky. A potential Roman ultra deep field could be far faster to capture, it cover hundreds of times as much of the early universe. To further explore this potential. A team of researchers has created a simulated ultra deep field image.

The entire image contains about one square degree of sky, or about five full moons. Even a single Roman field of view contains a staggering number of distant galaxies, each one filled with billions of stars.

This computer generated image represents the distribution of galaxies that researchers expect to find based on the existing Hubble observations. It will help astronomers determine how best to conduct an actual Roman ultra deep field and anticipate the measurement and conclusions they might be able to make. Because light travels at a finite speed, distant images are also snapshots earlier in time.

Ultra deep field images reveal a time from about 200 million to 1 billion years after the Big Bang. Romans image would be the largest observation of its kind for this time period and could reveal key features in the adolescent universe, including rare infant galaxies that eventually evolve into mature galaxies like our own Milky Way. With Roman set to launch by 2027, this simulated ultra deep field image is just one example of the fantastic results this upcoming mission could bring by the end of the decade.