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By NASA
This artist’s concept shows how the universe might have looked when it was less than a billion years old, about 7 percent of its current age. Star formation voraciously consumed primordial hydrogen, churning out myriad stars at an unprecedented rate. NASA’s Nancy Grace Roman Space Telescope will peer back to the universe’s early stages to understand how it transitioned from being opaque to the brilliant starscape we see today.NASA, ESA, and A. Schaller (for STScI) 0:00 / 0:00
Your browser does not support the audio element. Today, enormous stretches of space are crystal clear, but that wasn’t always the case. During its infancy, the universe was filled with a “fog” that made it opaque, cloaking the first stars and galaxies. NASA’s upcoming Nancy Grace Roman Space Telescope will probe the universe’s subsequent transition to the brilliant starscape we see today –– an era known as cosmic dawn.
“Something very fundamental about the nature of the universe changed during this time,” said Michelle Thaller, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Thanks to Roman’s large, sharp infrared view, we may finally figure out what happened during a critical cosmic turning point.”
Lights Out, Lights On
Shortly after its birth, the cosmos was a blistering sea of particles and radiation. As the universe expanded and cooled, positively charged protons were able to capture negatively charged electrons to form neutral atoms (mostly hydrogen, plus some helium). That was great news for the stars and galaxies the atoms would ultimately become, but bad news for light!
It likely took a long time for the gaseous hydrogen and helium to coalesce into stars, which then gravitated together to form the first galaxies. But even when stars began to shine, their light couldn’t travel very far before striking and being absorbed by neutral atoms. This period, known as the cosmic dark ages, lasted from around 380,000 to 200 million years after the big bang.
Then the fog slowly lifted as more and more neutral atoms broke apart over the next several hundred million years: a period called the cosmic dawn.
“We’re very curious about how the process happened,” said Aaron Yung, a Giacconi Fellow at the Space Telescope Science Institute in Baltimore, who is helping plan Roman’s early universe observations. “Roman’s large, crisp view of deep space will help us weigh different explanations.”
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Your browser does not support the audio element. Prime Suspects
It could be that early galaxies may be largely to blame for the energetic light that broke up the neutral atoms. The first black holes may have played a role, too. Roman will look far and wide to examine both possible culprits.
“Roman will excel at finding the building blocks of cosmic structures like galaxy clusters that later form,” said Takahiro Morishita, an assistant scientist at Caltech/IPAC in Pasadena, California, who has studied cosmic dawn. “It will quickly identify the densest regions, where more ‘fog’ is being cleared, making Roman a key mission to probe early galaxy evolution and the cosmic dawn.”
The earliest stars were likely starkly different from modern ones. When gravity began pulling material together, the universe was very dense. Stars probably grew hundreds or thousands of times more massive than the Sun and emitted lots of high-energy radiation. Gravity huddled up the young stars to form galaxies, and their cumulative blasting may have once again stripped electrons from protons in bubbles of space around them.
“You could call it the party at the beginning of the universe,” Thaller said. “We’ve never seen the birth of the very first stars and galaxies, but it must have been spectacular!”
But these heavyweight stars were short-lived. Scientists think they quickly collapsed, leaving behind black holes –– objects with such extreme gravity that not even light can escape their clutches. Since the young universe was also smaller because it hadn’t been expanding very long, hordes of those black holes could have merged to form even bigger ones –– up to millions or even billions of times the Sun’s mass.
Supermassive black holes may have helped clear the hydrogen fog that permeated the early universe. Hot material swirling around black holes at the bright centers of active galaxies, called quasars, prior to falling in can generate extreme temperatures and send off huge, bright jets of intense radiation. The jets can extend for hundreds of thousands of light-years, ripping the electrons from any atom in their path.
NASA’s James Webb Space Telescope is also exploring cosmic dawn, using its narrower but deeper view to study the early universe. By coupling Webb’s observations with Roman’s, scientists will generate a much more complete picture of this era.
So far, Webb is finding more quasars than anticipated given their expected rarity and Webb’s small field of view. Roman’s zoomed-out view will help astronomers understand what’s going on by seeing how common quasars truly are, likely finding tens of thousands compared to the handful Webb may find.
This view from the James Webb Space Telescope contains more than 20,000 galaxies. Researchers analyzed 117 galaxies that all existed approximately 900 million years after the big bang. They focused on 59 galaxies that lie in front of quasar J0100+2802, an active supermassive black hole that acts like a beacon, located at the center of the image above appearing tiny and pink with six prominent diffraction spikes. The team studied both the galaxies themselves and the illuminated gas surrounding them, which was lit up by the quasar’s bright light. The observation sheds light on how early galaxies cleared the “fog” around them, eventually leading to today’s clear and expansive views.NASA, ESA, CSA, Simon Lilly (ETH Zürich), Daichi Kashino (Nagoya University), Jorryt Matthee (ETH Zürich), Christina Eilers (MIT), Rob Simcoe (MIT), Rongmon Bordoloi (NCSU), Ruari Mackenzie (ETH Zürich); Image Processing: Alyssa Pagan (STScI), Ruari Macken “With a stronger statistical sample, astronomers will be able to test a wide range of theories inspired by Webb observations,” Yung said.
Peering back into the universe’s first few hundred million years with Roman’s wide-eyed view will also help scientists determine whether a certain type of galaxy (such as more massive ones) played a larger role in clearing the fog.
“It could be that young galaxies kicked off the process, and then quasars finished the job,” Yung said. Seeing the size of the bubbles carved out of the fog will give scientists a major clue. “Galaxies would create huge clusters of bubbles around them, while quasars would create large, spherical ones. We need a big field of view like Roman’s to measure their extent, since in either case they’re likely up to millions of light-years wide –– often larger than Webb’s field of view.”
Roman will work hand-in-hand with Webb to offer clues about how galaxies formed from the primordial gas that once filled the universe, and how their central supermassive black holes influenced galaxy and star formation. The observations will help uncover the cosmic daybreakers that illuminated our universe and ultimately made life on Earth possible.
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 and Caltech/IPAC in Southern 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.
Download high-resolution video and images from NASA’s Scientific Visualization Studio
By Ashley Balzer
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Media contact:
Claire Andreoli
claire.andreoli@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
301-286-1940
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Article 8 months ago 5 min read How NASA’s Roman Mission Will Hunt for Primordial Black Holes
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Last Updated Jul 25, 2024 ContactAshley Balzerashley.m.balzer@nasa.govLocationGoddard Space Flight Center Related Terms
Nancy Grace Roman Space Telescope Active Galaxies Astrophysics Black Holes Galaxies Galaxies, Stars, & Black Holes Galaxies, Stars, & Black Holes Research Goddard Space Flight Center James Webb Space Telescope (JWST) Origin & Evolution of the Universe Science & Research Stars Supermassive Black Holes The Big Bang The Universe View the full article
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By NASA
5 min read
NASA: Life Signs Could Survive Near Surfaces of Enceladus and Europa
Europa, a moon of Jupiter, and Enceladus, a moon of Saturn, have evidence of oceans beneath their ice crusts. A NASA experiment suggests that if these oceans support life, signatures of that life in the form of organic molecules (e.g. amino acids, nucleic acids, etc.) could survive just under the surface ice despite the harsh radiation on these worlds. If robotic landers are sent to these moons to look for life signs, they would not have to dig very deep to find amino acids that have survived being altered or destroyed by radiation.
“Based on our experiments, the ‘safe’ sampling depth for amino acids on Europa is almost 8 inches (around 20 centimeters) at high latitudes of the trailing hemisphere (hemisphere opposite to the direction of Europa’s motion around Jupiter) in the area where the surface hasn’t been disturbed much by meteorite impacts,” said Alexander Pavlov of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of a paper on the research published July 18 in Astrobiology. “Subsurface sampling is not required for the detection of amino acids on Enceladus – these molecules will survive radiolysis (breakdown by radiation) at any location on the Enceladus surface less than a tenth of an inch (under a few millimeters) from the surface.”
The frigid surfaces of these nearly airless moons are likely uninhabitable due to radiation from both high-speed particles trapped in their host planet’s magnetic fields and powerful events in deep space, such as exploding stars. However, both have oceans under their icy surfaces that are heated by tides from the gravitational pull of the host planet and neighboring moons. These subsurface oceans could harbor life if they have other necessities, such as an energy supply as well as elements and compounds used in biological molecules.
Dramatic plumes, both large and small, spray water ice and vapor from many locations along the famed “tiger stripes” near the south pole of Saturn’s moon Enceladus. NASA/JPL/Space Science Institute The research team used amino acids in radiolysis experiments as possible representatives of biomolecules on icy moons. Amino acids can be created by life or by non-biological chemistry. However, finding certain kinds of amino acids on Europa or Enceladus would be a potential sign of life because they are used by terrestrial life as a component to build proteins. Proteins are essential to life as they are used to make enzymes which speed up or regulate chemical reactions and to make structures. Amino acids and other compounds from subsurface oceans could be brought to the surface by geyser activity or the slow churning motion of the ice crust.
This view of Jupiter’s icy moon Europa was captured by JunoCam, the public engagement camera aboard NASA’s Juno spacecraft, during the mission’s close flyby on Sept. 29, 2022. The picture is a composite of JunoCam’s second, third, and fourth images taken during the flyby, as seen from the perspective of the fourth image. North is to the left. The images have a resolution of just over 0.5 to 2.5 miles per pixel (1 to 4 kilometers per pixel).
As with our Moon and Earth, one side of Europa always faces Jupiter, and that is the side of Europa visible here. Europa’s surface is crisscrossed by fractures, ridges, and bands, which have erased terrain older than about 90 million years.
Citizen scientist Kevin M. Gill processed the images to enhance the color and contrast.
NASA/JPL-Caltech/SwRI/MSSS Image processing: Kevin M. Gill CC BY 3.0 To evaluate the survival of amino acids on these worlds, the team mixed samples of amino acids with ice chilled to about minus 321 Fahrenheit (-196 Celsius) in sealed, airless vials and bombarded them with gamma-rays, a type of high-energy light, at various doses. Since the oceans might host microscopic life, they also tested the survival of amino acids in dead bacteria in ice. Finally, they tested samples of amino acids in ice mixed with silicate dust to consider the potential mixing of material from meteorites or the interior with surface ice.
This image shows experiment samples loaded in the specially designed dewar which will be filled with liquid nitrogen shortly after and placed under gamma radiation. Notice that the flame-sealed test tubes are wrapped in cotton fabric to keep them together because test tubes become buoyant in liquid nitrogen and start floating around in the dewar, interfering with the proper radiation exposure. Candace Davison The experiments provided pivotal data to determine the rates at which amino acids break down, called radiolysis constants. With these, the team used the age of the ice surface and the radiation environment at Europa and Enceladus to calculate the drilling depth and locations where 10 percent of the amino acids would survive radiolytic destruction.
Although experiments to test the survival of amino acids in ice have been done before, this is the first to use lower radiation doses that don’t completely break apart the amino acids, since just altering or degrading them is enough to make it impossible to determine if they are potential signs of life. This is also the first experiment using Europa/Enceladus conditions to evaluate the survival of these compounds in microorganisms and the first to test the survival of amino acids mixed with dust.
The team found that amino acids degraded faster when mixed with dust but slower when coming from microorganisms.
“Slow rates of amino acid destruction in biological samples under Europa and Enceladus-like surface conditions bolster the case for future life-detection measurements by Europa and Enceladus lander missions,” said Pavlov. “Our results indicate that the rates of potential organic biomolecules’ degradation in silica-rich regions on both Europa and Enceladus are higher than in pure ice and, thus, possible future missions to Europa and Enceladus should be cautious in sampling silica-rich locations on both icy moons.”
A potential explanation for why amino acids survived longer in bacteria involves the ways ionizing radiation changes molecules — directly by breaking their chemical bonds or indirectly by creating reactive compounds nearby which then alter or break down the molecule of interest. It’s possible that bacterial cellular material protected amino acids from the reactive compounds produced by the radiation.
The research was supported by NASA under award number 80GSFC21M0002, NASA’s Planetary Science Division Internal Scientist Funding Program through the Fundamental Laboratory Research work package at Goddard, and NASA Astrobiology NfoLD award 80NSSC18K1140.
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Last Updated Jul 18, 2024 Editor wasteigerwald Contact wasteigerwald william.a.steigerwald@nasa.gov Location NASA Goddard Space Flight Center Related Terms
Astrobiology Enceladus Europa Goddard Space Flight Center The Search for Life The Solar System Explore More
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By NASA
Credit: NASA The United States and Saudi Arabia signed a framework agreement that opens new possibilities for cooperation with NASA in areas such as space science, exploration, aeronautics, space operations, education, and Earth science.
NASA Administrator Bill Nelson signed on behalf of the U.S., and CEO of the Saudi Space Agency Mohammed bin Saud Al-Tamimi signed on behalf of the Kingdom of Saudi Arabia.
“Building on my visit to Saudi Arabia earlier this year, I look forward to strengthening our cooperation for the future of exploration,” said Nelson. “We are living in the golden era of exploration – one that is rooted in partnership. This new agreement outlines how we’ll work together, and explore together, for the benefit of humanity.”
Known as the “Framework Agreement Between the Government of the United States of America and the Government of The Kingdom of Saudi Arabia on Cooperation in Aeronautics and the Exploration and Use of Airspace and Outer Space for Peaceful Purposes,” it establishes the overall legal framework to facilitate and strengthen mutually beneficial collaboration between the two countries.
“The agreement represents a turning point in the Kingdom’s journey towards building a strong and prosperous space sector,” said Saudi Space Agency Chairman Abdullah bin Amer Al-Swaha. “It reflects the Kingdom’s firm commitment to progress and innovation in the field of space, and its continuous efforts to enhance its position as an important partner on the global stage for space exploration and scientific discovery.”
The agreement also acknowledges the importance of the Artemis Accords, which Saudi Arabia signed in July 2022, for the transparent, safe, and responsible exploration of space. The commitments of the Artemis Accords, and efforts by the signatories to advance implementation of all its principles, support NASA’s Artemis campaign with its partners and other activities of the accords signatories.
The signing comes two months after Nelson’s visit to Saudi Arabia, where he met with Saudi Space Agency and other senior officials to discuss future partnerships and civil space cooperation for the broader U.S. and Saudi Arabia relationship.
In May 2023, two Saudi mission specialists, Ali Alqarni and Rayyanah Barnawi, were among a group of Axiom Mission-2 private astronauts who launched into orbit aboard a SpaceX Dragon from NASA’s Kennedy Space Center in Florida, highlighting international cooperation. The Axiom Space astronauts conducted scientific research, outreach, and commercial activities aboard the International Space Station.
For more information about NASA’s international partnerships, visit:
https://www.nasa.gov/oiir
-end-
Meira Bernstein / Elizabeth Shaw
Headquarters, Washington
202-358-1600
meira.b.bernstein@nasa.gov / elizabeth.a.shaw@nasa.gov
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Last Updated Jul 16, 2024 LocationNASA Headquarters Related Terms
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By NASA
5 Min Read NASA’s Hubble Traces Dark Matter in Dwarf Galaxy Using Stellar Motions
This NASA Hubble Space Telescope image reveals a section of the Draco dwarf galaxy. Credits:
NASA, ESA, Eduardo Vitral, Roeland van der Marel, and Sangmo Tony Sohn (STScI); Image processing: Joseph DePasquale (STScI) The qualities and behavior of dark matter, the invisible “glue” of the universe, continue to be shrouded in mystery. Though galaxies are mostly made of dark matter, understanding how it is distributed within a galaxy offers clues to what this substance is, and how it’s relevant to a galaxy’s evolution.
While computer simulations suggest dark matter should pile up in a galaxy’s center, called a density cusp, many previous telescopic observations have indicated that it is instead more evenly dispersed throughout a galaxy. The reason for this tension between model and observation continues to puzzle astronomers, reinforcing the mystery of dark matter.
A team of astronomers has turned toward NASA’s Hubble Space Telescope to try and clarify this debate by measuring the dynamic motions of stars within the Draco dwarf galaxy, a system located roughly 250,000 light-years from Earth. Using observations that spanned 18 years, they succeeded in building the most accurate three-dimensional understanding of stars’ movements within the diminutive galaxy. This required scouring nearly two decades of Hubble archival observations of the Draco galaxy.
A team of astronomers analyzed observations by NASA’s Hubble Space Telescope taken over a span of 18 years to measure the dynamic motions of stars within the Draco dwarf galaxy. The telescope’s extensive baseline and data archive enabled the team to build the most accurate three-dimensional map of the stars’ movements within the system. These improved measurements are helping to shed “light” on the mysterious qualities and behavior of dark matter, the universe’s invisible “glue.” The left image is from the Digitized Sky Survey (DSS). It presents a wider view of the region. The two right-side images are Hubble views. NASA, ESA, Eduardo Vitral, Roeland van der Marel, and Sangmo Tony Sohn (STScI), DSS; Image processing: Joseph DePasquale (STScI)
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“Our models tend to agree more with a cusp-like structure, which aligns with cosmological models,” said Eduardo Vitral of the Space Telescope Science Institute (STScI) in Baltimore and lead author of the study. “While we cannot definitively say all galaxies contain a cusp-like dark matter distribution, it’s exciting to have such well measured data that surpasses anything we’ve had before.”
Charting the Movements of Stars
To learn about dark matter within a galaxy, scientists can look to its stars and their movements that are dominated by the pull of dark matter. A common approach to measure the speed of objects moving in space is by the Doppler Effect – an observed change of the wavelength of light if a star is approaching or receding from Earth. Although this line-of-sight velocity can provide valuable insight, only so much can be gleaned from this one-dimensional source of information.
Besides moving closer or further away from us, stars also move across the sky, measured as their proper motion. By combining line-of-sight velocity with proper motions, the team created an unprecedented analysis of the stars’ 3D movements.
“Improvements in data and improvements in modeling usually go hand in hand,” explained Roeland van der Marel of STScI, a co-author of the paper who initiated the study more than 10 years ago. “If you don’t have very sophisticated data or only one-dimensional data, then relatively straightforward models can often fit. The more dimensions and complexity of data you gather, the more complex your models need to be to truly capture all the subtleties of the data.”
A Scientific Marathon (Not a Sprint)
Since dwarf galaxies are known to have a higher proportion of dark matter content than other types of galaxies, the team honed in on the Draco dwarf galaxy, which is a relatively small and spheroidal nearby satellite of the Milky Way galaxy.
“When measuring proper motions, you note the position of a star at one epoch and then many years later measure the position of that same star. You measure the displacement to determine how much it moved,” explained Sangmo Tony Sohn of STScI, another co-author of the paper and the principal investigator of the latest observational program. “For this kind of observation, the longer you wait, the better you can measure the stars shifting.”
The team analyzed a series of epochs spanning from 2004 to 2022, an extensive baseline that only Hubble could offer, due to the combination of its sharp stable vision and record time in operation. The telescope’s rich data archive helped decrease the level of uncertainty in the measurement of the stars’ proper motions. The precision is equivalent to measuring an annual shift a little less than the width of a golf ball as seen on the Moon from Earth.
With three dimensions of data, the team reduced the amount of assumptions applied in previous studies and considered characteristics specific to the galaxy – such as its rotation, and distribution of its stars and dark matter – in their own modeling efforts.
An Exciting Future
The methodologies and models developed for the Draco dwarf galaxy can be applied to other galaxies in the future. The team is already analyzing Hubble observations of the Sculptor dwarf galaxy and the Ursa Minor dwarf galaxy.
Studying dark matter requires observing different galactic environments, and also entails collaboration across different space telescope missions. For example, NASA’s upcoming Nancy Grace Roman Space Telescope will help reveal new details of dark matter’s properties among different galaxies thanks to its ability to survey large swaths of the sky.
“This kind of study is a long-term investment and requires a lot of patience,” reflected Vitral. “We’re able to do this science because of all the planning that was done throughout the years to actually gather these data. The insights we’ve collected are the result of a larger group of researchers that has been working on these things for many years.”
These results are accepted for publication in The Astrophysical Journal.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
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Claire Andreoli
NASA’s Goddard Space Flight Center, Greenbelt, MD
claire.andreoli@nasa.gov
Abigail Major and Ray Villard
Space Telescope Science Institute, Baltimore, MD
Science Contacts:
Eduardo Vitral, Roeland van der Marel, and Sangmo Tony Sohn
Space Telescope Science Institute, Baltimore, MD
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Last Updated Jul 11, 2024 Editor Andrea Gianopoulos Location NASA Goddard Space Flight Center Related Terms
Astrophysics Astrophysics Division Dark Matter Dark Matter & Dark Energy Goddard Space Flight Center Hubble Space Telescope Missions The Universe Keep Exploring Discover More Topics From NASA
Hubble Space Telescope
Since its 1990 launch, the Hubble Space Telescope has changed our fundamental understanding of the universe.
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