Nancy Grace Roman Space Telescope: uncovering the mysteries of dark matter, dark energy and exoplanets
- Launch:
- Mission duration: Five years (possibility of an additional five years)
- Mission status: Active
Dark energy and dark matter account for about 95% of the universe's matter and energy, and strongly influence how it behaves and evolves. Some astronomers are studying their nature and structure to understand the history of our universe. Others search for exoplanets (planets orbiting other stars beyond our solar system) that are potentially habitable and Earth-like.
The Nancy Grace Roman Space Telescope (Roman) is a NASA observatory that will help settle essential questions in the areas of dark energy, dark matter and exoplanets. It orbits about 1.5 million kilometres away at the second Sun-Earth Lagrange point (L2), the same as the James Webb Space Telescope.
Finding answers to cosmic mysteries
Recent advances in space telescopes have transformed astronomy, yet many cosmic mysteries remain unsolved. Roman has three main scientific objectives:
- Explore dark energy and how the universe has evolved throughout cosmic history
- Discover around 100,000 new exoplanets
- Understand what dark matter is made of and how it is distributed across galaxies
Dark matter and dark energy
Dark matter is an invisible form of matter thought to drive how stars and galaxies formed and evolved. Dark energy is the dominating force that is causing the universe to expand at an accelerated rate. Neither of them interacts with light and can only be detected from their gravitational effects on visible matter. The characteristics of dark matter and dark energy remain some of the biggest mysteries of modern astronomical exploration.
With Hubble-level resolution and a field of view 100 times larger, Roman will capture images from the visible to near-infrared wavelengths and map matter. It will provide the most comprehensive 3D map of the distribution of galaxies and galaxy clusters across the universe.
Roman will study how matter in the universe has changed over time by measuring how the gravity from the otherwise invisible dark matter bends the path of light as it travels through space. Objects with mass can bend space-time, which slightly changes the path of light. This phenomenon is called gravitational lensing. Roman will use this effect to see where dark matter is, including smaller clumps that are hard to detect.
Dark matter's gravity slows the universe's expansion, while dark energy speeds it up. Roman will help astronomers build a 3D map of dark matter that will allow scientists to learn more about dark energy. By studying how these two forces have shaped the universe, astronomers may better understand how and why dark energy is making the universe expand faster.
Roman will measure the locations and quantities of both normal matter and dark matter in hundreds of millions of galaxies. Through several complementary techniques, it will also gather unprecedented data on dark energy. It will support astronomers in their quest to understand dark energy and dark matter's true nature and impact on the universe.
Exoplanets
Roman will survey planetary systems across the galaxy and test direct-imaging technologies up to 1,000 times more sensitive than other observatories. It will observe exoplanets and planet-forming disks indirectly and directly.
It will also allow scientists to study their atmosphere, reflectivity, temperatures and climates to better understand what planetary systems throughout the galaxy are like and how planets form and evolve
Roman will use its wide, deep view to study exoplanets in three complementary ways: gravitational microlensing, transit detection method, and direct imaging.
- Gravitational microlensing: Light normally travels in a straight line. However, when it passes near a massive object, such as a star, the star's gravity bends space-time and causes the light to curve. This curving of the light acts as a lens, making the object appear momentarily brighter. Planets orbiting that star can create additional, smaller distortions in the light. By analyzing these distortions, astronomers can determine a planet's mass and its distance from the host star. Roman will monitor the light from hundreds of millions of stars.
- Transit detection: This method has helped astronomers find most of the known exoplanets. The planet is detected when it crosses the face of its host star as it completes an orbit, which blocks some of the star's light.
- Direct imaging: Because exoplanets are extremely faint compared to their host stars, most have been discovered indirectly by observing their effects on the stars they orbit. Roman will use a powerful instrument to block only the light from the host star and capture detailed images of planets and dust disks around nearby systems. It will be able to detect smaller, older, and cooler planets than current direct-imaging methods, helping pave the way toward photographing Earth-like worlds.
By combining these techniques and a wide-field, Roman is predicted to find around 100,000 new exoplanets and greatly improve our understanding of planetary systems in our galaxy.
Canada's role in the mission
Canadian technology on board the telescope
The Nancy Grace Roman Space Telescope is equipped with two ultra-sensitive cameras developed by two Canadian companies: Nüvü Cameras and ABB. Able to capture extremely low light, the cameras will support searches for distant worlds and tiny orbital debris while helping meet Roman's demanding science objectives.
Through its Space Technology Development Program (STDP), the Canadian Space Agency (CSA) supported Nüvü's ultrasensitive imaging technology, beginning with a 2010 contract to assess its cameras for space. This led to a lasting CSA–Nüvü collaboration advancing Canadian imaging technology for space missions.
ABB supplied advanced electronic components for the cameras on the Nancy Grace Roman Space Telescope, drawing on expertise developed through its contributions to major international space missions. Together, Nüvü and ABB have helped develop some of the most sensitive cameras ever built for space science.
Canadian research projects supporting Roman's mission
The CSA is funding two scientists' participation in the Roman mission through the Research Opportunities in Space Science program:
- Dr. Kelsey Hoffman of Bishop's University aims to demonstrate the telescope's ability to detect transiting exoplanets. The project will optimize tools and methods to help Roman find and study these planets.
- Dr. Will Percival of the University of Waterloo will use data from both Roman and Euclid to study dark matter, dark energy and the universe's evolution.
Dr. Will Percival, professor and Distinguished Research Chair in Astrophysics at the University of Waterloo. (Credit: University of Waterloo)
Dr. Kesley Hoffman, adjunct professor in the Department of Physics and Astronomy, Bishop's University. (Credit: Bishop's University)