NASA's Roman Space Telescope Set to Launch, Promising New View of Universe

According to NPR News, the telescope has an unusual history. About 15 years ago, NASA was planning a space telescope to search for Type 1A supernovas, which were used as cosmological measuring sticks to uncover dark energy, a discovery that earned the Nobel Prize in 2011. Later, the National Reconnaissance Office offered NASA an unused surveillance satellite, which after substantial modifications became the Roman telescope.

Cosmologist Daniel Scolnic at Duke University said finding more supernovas would be key to understanding the universe's expansion. He added that the new observatory could fundamentally test the current model of the universe. "In the last few years, there have been measurements saying that model might be wrong — and that's something that Roman will absolutely nail, whether the model's right or wrong," he said.

The telescope will also spend a month surveying all the stars in the Milky Way. Julie McEnery, Roman's project scientist, noted that while Roman has similar sensitivity to Hubble, its survey capability is far faster. "That one month of observations to survey our Milky Way galaxy would take about a century with Hubble," she said. She also emphasized that data will be public, allowing high school teachers and students to access it at the same time as professors at Princeton.

Another goal is detecting planets via gravitational microlensing, a technique developed by Scott Gaudi at Ohio State University. Gaudi expects Roman to find planets undetectable by other methods, including worlds analogous to Jupiter, Saturn, Uranus, and Neptune at the galaxy's center. The telescope should also reveal new galaxies, helping astronomers understand large-scale structure.

Predicting Roman's greatest accomplishments over its five-year mission is difficult. Astronomer Wendy Freedman of the University of Chicago said, "The history of astronomy really has shown that when you get a new capability, and especially a survey capability, you learn something new, something unexpected. Often that turns out to be the most exciting part of a new facility. So I am completely open to what this telescope will find."