Members Can Post Anonymously On This Site
-
Similar Topics
-
By European Space Agency
Astronomers have discovered a huge filament of hot gas bridging four galaxy clusters. At 10 times as massive as our galaxy, the thread could contain some of the Universe’s ‘missing’ matter, addressing a decades-long mystery.
View the full article
-
By NASA
A funky effect Einstein predicted, known as gravitational lensing — when a foreground galaxy magnifies more distant galaxies behind it — will soon become common when NASA’s Nancy Grace Roman Space Telescope begins science operations in 2027 and produces vast surveys of the cosmos.
This image shows a simulated observation from NASA’s Nancy Grace Roman Space Telescope with an overlay of its Wide Field Instrument’s field of view. More than 20 gravitational lenses, with examples shown at left and right, are expected to pop out in every one of Roman’s vast observations. A journal paper led by Bryce Wedig, a graduate student at Washington University in St. Louis, Missouri, estimates that of those Roman detects, about 500 from the telescope’s High-Latitude Wide-Area Survey will be suitable for dark matter studies. By examining such a large population of gravitational lenses, the researchers hope to learn a lot more about the mysterious nature of dark matter.Credit: NASA, Bryce Wedig (Washington University), Tansu Daylan (Washington University), Joseph DePasquale (STScI) A particular subset of gravitational lenses, known as strong lenses, is the focus of a new paper published in the Astrophysical Journal led by Bryce Wedig, a graduate student at Washington University in St. Louis. The research team has calculated that over 160,000 gravitational lenses, including hundreds suitable for this study, are expected to pop up in Roman’s vast images. Each Roman image will be 200 times larger than infrared snapshots from NASA’s Hubble Space Telescope, and its upcoming “wealth” of lenses will vastly outpace the hundreds studied by Hubble to date.
Roman will conduct three core surveys, providing expansive views of the universe. This science team’s work is based on a previous version of Roman’s now fully defined High-Latitude Wide-Area Survey. The researchers are working on a follow-up paper that will align with the final survey’s specifications to fully support the research community.
“The current sample size of these objects from other telescopes is fairly small because we’re relying on two galaxies to be lined up nearly perfectly along our line of sight,” Wedig said. “Other telescopes are either limited to a smaller field of view or less precise observations, making gravitational lenses harder to detect.”
Gravitational lenses are made up of at least two cosmic objects. In some cases, a single foreground galaxy has enough mass to act like a lens, magnifying a galaxy that is almost perfectly behind it. Light from the background galaxy curves around the foreground galaxy along more than one path, appearing in observations as warped arcs and crescents. Of the 160,000 lensed galaxies Roman may identify, the team expects to narrow that down to about 500 that are suitable for studying the structure of dark matter at scales smaller than those galaxies.
“Roman will not only significantly increase our sample size — its sharp, high-resolution images will also allow us to discover gravitational lenses that appear smaller on the sky,” said Tansu Daylan, the principal investigator of the science team conducting this research program. Daylan is an assistant professor and a faculty fellow at the McDonnell Center for the Space Sciences at Washington University in St. Louis. “Ultimately, both the alignment and the brightness of the background galaxies need to meet a certain threshold so we can characterize the dark matter within the foreground galaxies.”
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
This video shows how a background galaxy’s light is lensed or magnified by a massive foreground galaxy, seen at center, before reaching NASA’s Roman Space Telescope. Light from the background galaxy is distorted, curving around the foreground galaxy and appearing more than once as warped arcs and crescents. Researchers studying these objects, known as gravitational lenses, can better characterize the mass of the foreground galaxy, which offers clues about the particle nature of dark matter.Credit: NASA, Joseph Olmsted (STScI) What Is Dark Matter?
Not all mass in galaxies is made up of objects we can see, like star clusters. A significant fraction of a galaxy’s mass is made up of dark matter, so called because it doesn’t emit, reflect, or absorb light. Dark matter does, however, possess mass, and like anything else with mass, it can cause gravitational lensing.
When the gravity of a foreground galaxy bends the path of a background galaxy’s light, its light is routed onto multiple paths. “This effect produces multiple images of the background galaxy that are magnified and distorted differently,” Daylan said. These “duplicates” are a huge advantage for researchers — they allow multiple measurements of the lensing galaxy’s mass distribution, ensuring that the resulting measurement is far more precise.
Roman’s 300-megapixel camera, known as its Wide Field Instrument, will allow researchers to accurately determine the bending of the background galaxies’ light by as little as 50 milliarcseconds, which is like measuring the diameter of a human hair from the distance of more than two and a half American football fields or soccer pitches.
The amount of gravitational lensing that the background light experiences depends on the intervening mass. Less massive clumps of dark matter cause smaller distortions. As a result, if researchers are able to measure tinier amounts of bending, they can detect and characterize smaller, less massive dark matter structures — the types of structures that gradually merged over time to build up the galaxies we see today.
With Roman, the team will accumulate overwhelming statistics about the size and structures of early galaxies. “Finding gravitational lenses and being able to detect clumps of dark matter in them is a game of tiny odds. With Roman, we can cast a wide net and expect to get lucky often,” Wedig said. “We won’t see dark matter in the images — it’s invisible — but we can measure its effects.”
“Ultimately, the question we’re trying to address is: What particle or particles constitute dark matter?” Daylan added. “While some properties of dark matter are known, we essentially have no idea what makes up dark matter. Roman will help us to distinguish how dark matter is distributed on small scales and, hence, its particle nature.”
Preparations Continue
Before Roman launches, the team will also search for more candidates in observations from ESA’s (the European Space Agency’s) Euclid mission and the upcoming ground-based Vera C. Rubin Observatory in Chile, which will begin its full-scale operations in a few weeks. Once Roman’s infrared images are in hand, the researchers will combine them with complementary visible light images from Euclid, Rubin, and Hubble to maximize what’s known about these galaxies.
“We will push the limits of what we can observe, and use every gravitational lens we detect with Roman to pin down the particle nature of dark matter,” Daylan said.
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems, Inc. in Boulder, Colorado; L3Harris Technologies in Melbourne, Florida; and Teledyne Scientific & Imaging in Thousand Oaks, California.
By Claire Blome
Space Telescope Science Institute, Baltimore, Md.
Share
Details
Last Updated Jun 12, 2025 EditorAshley BalzerContactAshley Balzerashley.m.balzer@nasa.govLocationNASA Goddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Astrophysics Dark Matter Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research The Universe Explore More
6 min read NASA’s Roman Mission Shares Detailed Plans to Scour Skies
Article 2 months ago 5 min read Millions of Galaxies Emerge in New Simulated Images From NASA’s Roman
Article 2 years ago 6 min read Team Preps to Study Dark Energy via Exploding Stars With NASA’s Roman
Article 3 months ago View the full article
-
By NASA
The core portion of NASA’s Nancy Grace Roman Space Telescope has successfully completed vibration testing, ensuring it will withstand the extreme shaking experienced during launch. Passing this key milestone brings Roman one step closer to helping answer essential questions about the role of dark energy and other cosmic mysteries.
“The test could be considered as powerful as a pretty severe earthquake, but there are key differences,” said Cory Powell, the Roman lead structural analyst at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Unlike an earthquake, we sweep through our frequencies one at a time, starting with very low-level amplitudes and gradually increasing them while we check everything along the way. It’s a very complicated process that takes extraordinary effort to do safely and efficiently.”
To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video
This video shows the core components of NASA’s Nancy Grace Roman Space Telescope undergoing a vibration test at the agency’s Goddard Space Flight Center. The test ensures this segment of the observatory will withstand the extreme shaking associated with launch. Credit: NASA’s Goddard Space Flight Center The team simulated launch conditions as closely as possible. “We performed the test in a flight-powered configuration and filled the propulsion tanks with approximately 295 gallons of deionized water to simulate the propellent loading on the spacecraft during launch,” said Joel Proebstle, who led this test, at NASA Goddard. This is part of a series of tests that ratchet up to 125 percent of the forces the observatory will experience.
This milestone is the latest in a period of intensive testing for the nearly complete Roman Space Telescope, with many major parts coming together and running through assessments in rapid succession. Roman currently consists of two major assemblies: the inner, core portion (telescope, instrument carrier, two instruments, and spacecraft) and the outer portion (outer barrel assembly, solar array sun shield, and deployable aperture cover).
Now, having completed vibration testing, the core portion will return to the large clean room at Goddard for post-test inspections. They’ll confirm that everything remains properly aligned and the high-gain antenna can deploy. The next major assessment for the core portion will involve additional tests of the electronics, followed by a thermal vacuum test to ensure the system will operate as planned in the harsh space environment.
This video highlights some of the important hardware milestones as NASA’s Nancy Grace Roman Space Telescope moves closer to completion. The observatory is almost fully assembled, currently built up into two large pieces: the inner portion (telescope, instrument carrier, two instruments, and spacecraft) and outer portion (outer barrel assembly, solar array sun shield, and deployable aperture cover). This video shows the testing these segments have undergone between February and May 2025. Credit: NASA’s Goddard Space Flight Center In the meantime, Goddard technicians are also working on Roman’s outer portion. They installed the test solar array sun shield, and this segment then underwent its own thermal vacuum test, verifying it will control temperatures properly in the vacuum of space. Now, technicians are installing the flight solar panels to this outer part of the observatory.
The team is on track to connect Roman’s two major assemblies in November, resulting in a whole observatory by the end of the year that will then undergo final tests. Roman remains on schedule for launch by May 2027, with the team aiming for as early as fall 2026.
Click here to virtually tour an interactive version of the telescope The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems Inc. in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Share
Details
Last Updated Jun 04, 2025 Related Terms
Nancy Grace Roman Space Telescope Goddard Space Flight Center Technology The Universe Explore More
3 min read Key Portion of NASA’s Roman Space Telescope Clears Thermal Vacuum Test
Article 4 weeks ago 6 min read How NASA’s Roman Space Telescope Will Illuminate Cosmic Dawn
Article 10 months ago 6 min read New Study Reveals NASA’s Roman Could Find 400 Earth-Mass Rogue Planets
Article 2 years ago View the full article
-
By NASA
NASA Dr. Nancy Grace Roman, NASA’s first Chief of Astronomy and namesake of the Nancy Grace Roman Telescope, briefs astronaut Edwin “Buzz” Aldrin on celestial objects in 1965 in Washington, D.C. Nancy Grace Roman passed away on December 25, 2018, in Germantown, Maryland at the age of 93. May 16, 2025, would have been her 100th birthday.
Prior to joining NASA in 1959, Dr. Roman was a well-respected and influential astronomer, publishing some of the most cited papers in the mid-20th century, one included in a list of 100 most influential papers in 100 years. At the agency, Roman worked to gain science support for space-based observatories. She established NASA’s scientific ballooning and airborne science, oversaw the start of the Great Observatory program with the first decade of Hubble Space Telescope development, and invested early in charge-coupled devices technology development used on Hubble – and now in digital cameras everywhere.
She was also key to the decision to link the development of the Large Space Telescope (that became Hubble) and the Space Transportation System – more commonly known as the Space Shuttle. Finally, after retiring from NASA, Dr. Roman often worked with young students in underserved communities, hoping her story and mentoring could inspire them to join humanity’s quest for knowledge in a STEM field.
Learn more about Dr. Roman.
Text credit: NASA/Jackie Townsend
Image credit: NASA
View the full article
-
By NASA
One half of NASA’s nearly complete Nancy Grace Roman Space Telescope just passed a lengthy test to ensure it will function properly in the space environment. This milestone keeps Roman well on track for its target launch by May 2027, with the team aiming for as early as fall 2026.
This photo shows half of the NASA’s Nancy Grace Roman observatory — the outer barrel assembly, deployable aperture cover, and test solar arrays — fully deployed in a thermal chamber at NASA’s Goddard Space Flight Center in Greenbelt, Md., for environmental testing. Credit: NASA/Sydney Rohde “This milestone tees us up to attach the flight solar array sun shield to the outer barrel assembly, and deployable aperture cover, which we’ll begin this month,” said Jack Marshall, who leads integration and testing for these elements at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Then we’ll complete remaining environmental tests for the flight assembly before moving on to connect Roman’s two major assemblies and run the full observatory through testing, and then we’ll be ready to launch!”
Prior to this thermal testing, technicians integrated Roman’s deployable aperture cover, a visor-like sunshade, to the outer barrel assembly, which will house the telescope and instruments, in January, then added test solar panels in March. They moved this whole structure into the Space Environment Simulator test chamber at NASA Goddard in April.
There, it was subjected to the hot and cold temperatures it will experience in space. Next, technicians will join Roman’s flight solar panels to the outer barrel assembly and sunshade. Then the structure will undergo a suite of assessments, including a shake test to ensure it can withstand the vibrations experienced during launch.
This photo captures the installation of the test solar panels for NASA’s Nancy Grace Roman Space Telescope, which took place in March. One panel is lifted in the center of the frame on its way to being attached to the outer barrel assembly at right. The deployable aperture cover is stowed on the front of the outer barrel assembly, and the other half of the observatory — the spacecraft and integrated payload assembly, which consists of the telescope, instrument carrier, and two instruments — appears at the left of the photo.Credit: NASA/Jolearra Tshiteya Meanwhile, Roman’s other major portion — the spacecraft and integrated payload assembly, which consists of the telescope, instrument carrier, and two instruments — will undergo its own shake test, along with additional assessments. Technicians will install the lower instrument sun shade and put this half of the observatory through a thermal vacuum test in the Space Environment Simulator.
“The test verifies the instruments will remain at stable operating temperatures even while the Sun bakes one side of the observatory and the other is exposed to freezing conditions — all in a vacuum, where heat doesn’t flow as readily as it does through air,” said Jeremy Perkins, an astrophysicist serving as Roman’s observatory integration and test scientist at NASA Goddard. Keeping the instrument temperatures stable ensures their readings will be precise and reliable.
Technicians are on track to connect Roman’s two major parts in November, resulting in a complete observatory by the end of the year. Following final tests, Roman is expected to ship to the launch site at NASA’s Kennedy Space Center in Florida for launch preparations in summer 2026. Roman remains on schedule for launch by May 2027, with the team aiming for launch as early as fall 2026.
This infographic shows the two major subsystems that make up NASA’s Nancy Grace Roman Space Telescope. The subsystems are each undergoing testing prior to being joined together this fall.Credit: NASA’s Goddard Space Flight Center To virtually tour an interactive version of the telescope, visit:
https://roman.gsfc.nasa.gov/interactive
The Nancy Grace Roman Space Telescope is managed at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with participation by NASA’s Jet Propulsion Laboratory in Southern California; Caltech/IPAC in Pasadena, California; the Space Telescope Science Institute in Baltimore; and a science team comprising scientists from various research institutions. The primary industrial partners are BAE Systems Inc. in Boulder, Colorado; L3Harris Technologies in Rochester, New York; and Teledyne Scientific & Imaging in Thousand Oaks, California.
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media Contact:
Claire Andreoli
NASA’s Goddard Space Flight Center
301-286-1940
Share
Details
Last Updated May 07, 2025 EditorAshley BalzerContactAshley Balzerashley.m.balzer@nasa.govLocationNASA Goddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Goddard Space Flight Center Technology Explore More
6 min read NASA’s Roman Mission Shares Detailed Plans to Scour Skies
Article 2 weeks ago 6 min read Team Preps to Study Dark Energy via Exploding Stars With NASA’s Roman
Article 2 months ago 6 min read How NASA’s Roman Space Telescope Will Illuminate Cosmic Dawn
Article 10 months ago View the full article
-
-
Check out these Videos
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.