NASA will soon be launching a new space observatory. On Aug. 30, 2026, the Nancy Grace Roman Space Telescope will join the likes of Hubble and the James Webb Space Telescope, collecting data and taking images that astronomers hope will unlock some of the universe’s biggest secrets.
One of its main tasks will be to map distant planets that lie beyond the Solar System (also known as exoplanets). Today, there are just 6,200 exoplanets known to science, but it is hoped that this number will snowball, in large part thanks to Roman and the detailed surveys it will be able to conduct at impressive speed.
Roman’s Hunt For New Worlds
It wasn’t that long ago that the only planets we knew of were those that existed in our Solar System. The first exoplanet was not discovered until 1992, according to the European Space Agency.
While the number has multiplied in recent years, Roman will accelerate the process. During its initial 5-year mission, it is expected to add up to 100,000 new exoplanets to the current catalog — from Jupiter-like gas planets to smaller, colder worlds up to a tenth of the Earth’s mass, according to the Infrared Processing and Analysis Center.
It’s also expected to gather data that will help astronomers understand the diversity, properties, and evolution of distant planetary systems.
Explore All OptionsTo do so, it will adopt three methods: transits, microlensing and direct imaging.
Method 1: Transits
Transits are, currently, astronomers’ most effective tool for finding new planets. Roman is expected to find another 100,000 exoplanets using this technique alone.
It will do so by capturing momentary dips in starlight that occur when a planet crosses its host star, blocking its light.
But there is a catch. While great at detecting larger, Jupiter-like worlds that orbit closer to their host star, some smaller planets are harder to detect.
Method 2: Microlensing
Luckily, there is a second technique that should enable astronomers to identify planets as small as Mars: microlensing.
Roman has an exceptional field view, which is at least a hundred times larger than Hubble. This will enable the telescope to observe hundreds of millions of stars across the galaxy and detect subtle changes in starlight, called microlensing events.
These are temporary spikes of brightness that occur when the mass of one star causes the light of another (more distant) star to curve. This happens when the two stars appear close from our viewpoint and the second (nearer) star magnifies the light of the other.
Because planets can also affect the travel of starlight, the technique can be used to detect those orbiting the second star within its habitable zone. It’s thought Roman will be able to add thousands more exoplanets to the catalog using this method.
Read More: How Nancy Grace Roman, the ‘Mother of Hubble,’ Became the Namesake of NASA’s New Telescope
Method 3: Testing Direct Imaging
The final method is direct imaging. Roman contains exceptionally powerful technology capable of capturing detailed images of the dusty disks surrounding nearby stars, and experts hope to test its capabilities during this mission.
According to NASA, the telescope will be able to do so with a sensitivity a thousand times greater than that of other observatories thanks to the addition of the Coronagraph — an intricate system of optics, masks, mirrors, and sensors.
The Coronagraph will block starlight that could obscure planets. As such, Roman's coronagraph will directly image some giant exoplanets and debris disks while demonstrating technologies that future missions may use to image Earth-like worlds.
Dark Energy, Dark Matter And More
But it doesn’t stop there. As well as hunting for new worlds, Roman will collect data that scientists hope will shed light on some of the universe’s most enduring mysteries, including dark matter and dark energy.
Even this could just be the beginning when it comes to Roman’s contribution to the field of astronomy.
“There are many science advancements that can be directly quantified by planned Roman improvements, but perhaps the most exciting and memorable will be the ones that we couldn't have anticipated,” Christina Lindberg, a postdoc at the Center for Astrophysics at Harvard, told Discover. “[Roman’s] capabilities will help us answer questions about the evolution of stars, the 3D structure of galaxies, and the compact-object populations behind gravitational wave sources.”
Read More: JWST Revealed the Early Universe — The Roman Space Telescope Will Help Us Understand How It Evolved
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from NASA: Exoplanets
- This article references information from NASA: Nancy Grace Roman Space Telescope press kit
- This article references information from the ESA: Exoplanet
- This article references information from the Infrared Processing and Analysis Center: Nancy Grace Roman Space Telescope
