#NASA; #BlackHistoryMonth; #RetiredAirForceColCharlesMcGee; #TuskegeeAirman
Washington, Jan 31 (Canadian-Media): As part of its celebration of Black History Month, NASA will honor retired Air Force Col. Charles McGee at a ceremony Wednesday, Feb. 5, in the James Webb Auditorium at NASA Headquarters, located at 300 E Street SW in Washington, NASA news release said.
Retired Air Force Col. Charles McGee, one of nine surviving combat pilots who served with the Tuskegee Airmen during World War II. At age 100, McGee will share his experiences during a ceremony honoring him at NASA Headquarters on Wednesday, Feb. 5, as part of the agency's celebration of Black History Month. Image Credits: Eddie Kyle Photography/Edward Kyle
The event, sponsored by the NASA Headquarters chapter of Blacks in Government, will begin at 11:30 a.m. EST and will air live on NASA TV and the agency’s website.
McGee, who served as a pilot with the Tuskegee Airmen during World War II – known at the time as the “Red Tails” – was a career officer in the Air Force and also served during the Korean and Vietnam wars, having flown 409 combat missions during his 30 years of service. Of the 355 Tuskegee pilots who flew in combat, McGee is one of only nine surviving. McGee is scheduled to receive an honorary promotion to the rank of brigadier general, as authorized by the National Defense Authorization Act for Fiscal Year 2020, which President Trump signed into law in December, the same month McGee celebrated his 100th birthday.
McGee will be joined by NASA astronaut Alvin Drew, also a retired Air Force colonel, who logged more than 612 hours in space on space shuttle Endeavor on the STS-118 mission in 2007 and space shuttle Discovery on STS-133 in 2011. The two will share their experiences on what it means to be a trailblazer and to inspire others to follow their dreams.
The event also will feature a vocal performance by the Jubilee Singers of All Souls Church, Unitarian, in Washington.
Media interested in attending must send their name, affiliation and phone number to Sean Potter at email@example.com no later than 8 a.m. Feb. 5.
#NASA; #OceanObservationSatellite; #ESA; #EC; #EUMETSAT; #NOAA; #Sentinel6A/JasonCSSatellite; #Sentinel6AMichaelFreilich, #Sentinel6B; #CNES; #EU
Washington, Jan 28 (Canadian-Media): NASA and several partners announced Tuesday they have renamed a key ocean observation satellite launching this fall in honor of Earth scientist Michael Freilich, who retired last year as head of NASA’s Earth Science division, a position he held since 2006, NASA news release reported today.
The Sentinel-6A satellite, which NASA and several partners have renamed in honor of noted Earth scientist Michael Freilich. Image Credits: ESA/NASA
NASA – along with ESA (European Space Agency), the European Commission (EC), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Oceanic and Atmospheric Administration (NOAA) – made the announcement during a special event at the agency’s headquarters.
“This honor demonstrates the global reach of Mike’s legacy,” said NASA Administrator Jim Bridenstine. “We are grateful for ESA and the European partners’ generosity in recognizing Mike’s lifelong dedication to understanding our planet and improving life for everyone on it. Mike’s contributions to NASA – and to Earth science worldwide – have been invaluable, and we are thrilled that this satellite bearing his name will uncover new knowledge about the oceans for which he has such an abiding passion.”
The Sentinel-6A/Jason CS satellite, scheduled to launch this fall from Vandenberg Air Force base in California, will now be known as Sentinel-6 Michael Freilich. The mission aims to continue high precision ocean altimetry measurements in the 2020/2030 timeframe using two identical satellites launching five years apart – Sentinel-6A Michael Freilich and Sentinel-6B.
NASA and its partners are developing the mission with support from the Centre National d'Etudes Spatiales (CNES), France's space agency. ESA is developing the new Sentinel family of missions specifically to support the operational needs of the European Union’s Copernicus program, the EU’s Earth observation program managed by the European Commission. They will replace older satellites nearing the end of their operational lifespan to ensure there are no gaps in ongoing land, atmosphere and ocean monitoring, as well as introduce new monitoring capabilities.
A key ocean observation satellite launching this fall has been named after Earth scientist Michael Freilich, as announced Jan. 28 by NASA, ESA (European Space Agency), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the National Oceanic and Atmospheric Administration (NOAA). Image Credits: NASA
“Together with other missions of the European Union’s Earth Observation Programme Copernicus, Sentinel-6 Michael Freilich will contribute to improved knowledge and understanding of the role of the ocean in climate change and for mitigation and adaptation policies in coastal areas,” said Mercedes Garcia Perez, head of the Global Issues and Innovation of the European Union Delegation to the United States. “It will have a large societal impact worldwide as it supports applications in the area of operational oceanography including ship routing, support for off-shore and other marine industries, fisheries, and responses to environmental hazards. This new satellite within the Copernicus constellation will be an additional tool for implementing the European Green Deal to transition the EU to a carbon neutral economy.”
A secondary objective of the Sentinel-6 mission is to collect high-resolution vertical profiles of temperature, using the Global Navigation Satellite Sounding Radio-Occultation sounding technique, which derives atmospheric information from analyses of signals from international Global Positioning System satellites. Sentinel-6 measurements of temperature changes in the troposphere and stratosphere will be used by weather agencies worldwide to improve the accuracy of global forecasts produced by their complex, state-of-the-art computer models.
The Sentinel-6 Michael Freilich satellite also will continue the existing 28-year data set of sea level changes measured from space. Before his retirement, Freilich was instrumental in advancing the collaborative mission to a critical stage of development and helping to strengthen its essential international partnerships.
“This mission demonstrates what the United States and Europe can achieve as equal partners in such a large space project. Our suggestion to rename the mission to ‘Sentinel-6 Michael Freilich’ is an expression of how thankful we are to Mike. Without him, this mission as it is today would not have been possible," said Josef Aschbacher, ESA director of Earth Observation Programmes.
Michael Freilich, who served as director of NASA’s Earth Science division from 2006-2019.
Freilich’s career as an oceanographer spanned nearly four decades and integrated research on Earth’s oceans, leading satellite mission development, and helping to train and inspire the next generation of scientific leaders. His training was in ocean physics, but his vision encompasses the full spectrum of Earth’s dynamics.
“Earth Science shows perhaps more than any other discipline how important partnership is to the future of this planet,” said Thomas Zurbuchen, NASA associate administrator for Science. “Mike exemplifies the commitment to excellence, generosity of spirit and unmatched ability to inspire trust that made so many people across the world want to advance big goals on behalf of our planet and all its people by working with NASA. The fact that ESA and the European partners have given him this unprecedented honor demonstrates that respect and admiration.”
During Freilich’s NASA tenure, the agency increased the pace of Earth science mission launches and in 2014 alone sent five missions to space to study our home planet. The missions balanced many objectives from research to applications and technology development activities. Freilich also led NASA’s response to the National Academy of Sciences’ first-ever Earth Science and Applications from Space decadal survey in 2007, which expanded NASA’s innovative Earth-observing programs and continues to guide the agency’s global Earth observation efforts.
"My NOAA colleagues and I enthusiastically support renaming Sentinel-6A after Mike," said Stephen Volz, assistant administrator for NOAA's Satellite and Information Service. "This is a fitting honor for a man who helped transform space-based Earth observation and has brought together the best contributions from our global Earth science community to improve our collective understanding of how our planet is changing." NOAA uses data from missions such as Sentinel-6 in a variety of ways, from monitoring the rate of global sea-level rise to producing more accurate weather forecasts.
Freilich also established the sustained Venture-Class program of low-cost space and airborne science missions that is now a central feature of the NASA Earth Science Division’s portfolio. He pioneered the broad use of the International Space Station as a platform for Earth-observing instruments, a unique observing platform for the Earth system. Unlike many of the traditional Earth observation platforms, the space station orbits Earth in an inclined equatorial orbit that is not sun-synchronous. This means the space station passes over locations between 52 degrees north and 52 degrees south latitude at different times of day and night, and under varying illumination conditions. This is particularly important for collecting imagery of unexpected natural hazard and disaster events such as volcanic eruptions, earthquakes, flooding and tsunamis, as well as for cross-calibrating other satellites in sun-synchronous polar orbits.
Freilich also inaugurated a NASA activity to use data products from private sector, small-satellite constellations and commercial partners to supplement traditional government data sources. Under Freilich’s leadership, NASA looked at new ways to carry out its critical mission and established cutting-edge programs to use small satellites and payloads hosted on commercial satellites to advance Earth science research and to demonstrate new technologies.
All told, during Freilich’s time at NASA Headquarters, he oversaw 16 successful major mission and instrument launches and eight CubeSat/small-satellite launches. The agency’s Earth Science Division has 14 Earth-observing missions in development for launch by 2023, which includes eight major hosted instruments on other nations’ satellites.
NASA uses the unique vantage point of space and suborbital platforms to better understand Earth as an interconnected system for societal benefit. The agency also develops new technologies and approaches to observe and study Earth with long-term data records, research, modeling, and computer analysis tools to quantify how our planet is changing. NASA shares this knowledge with the global community, including managers and policymakers domestically and internationally to understand and protect our home planet.
#NASA; #TributeToFallenSoldiers; #AnnualDayOfRemembrance
Washington, Jan 26 (Canadian-Media): NASA will honor members of the NASA family who lost their lives while furthering the cause of exploration and discovery, including the crews of Apollo 1 and space shuttles Challenger and Columbia, during the agency's annual Day of Remembrance Thursday, Jan. 30, NASA News release said on Jan 24.
NASA Administrator Jim Bridenstine speaks to NASA personnel and others during a wreath laying ceremony as part of NASA's Day of Remembrance, Thursday, Feb. 7, 2019, at Arlington National Cemetery in Arlington, Va. The wreaths were laid in memory of those men and women who lost their lives in the quest for space exploration.
Credits: NASA/Aubrey Gemignani
NASA Administrator Jim Bridenstine, along with other senior agency officials, will lead an observance at Arlington National Cemetery in Virginia beginning at 1 p.m. EST. A wreath-laying ceremony will take place at the Tomb of the Unknown Soldier, followed by observances for the Apollo 1, Challenger and Columbia crews.
Media interested in attending the remembrance event must contact Arlington National Cemetery Public Affairs at 703-614-0024 no later than noon Wednesday, Jan. 29.
Various NASA centers also will hold observances on and leading up to the Day of Remembrance for the public, employees and the families of those lost in service to America’s space program.
Kennedy Space Center, Florida
NASA’s Kennedy Space Center, in partnership with The Astronauts Memorial Foundation and Kennedy Space Center Visitor Complex, will host Day of Remembrance observance activities, including a wreath-laying ceremony at 10 a.m. at the Astronauts Memorial Foundation Space Mirror Memorial in the Kennedy Space Center Visitor Complex.
Thad Altman, president and chief executive officer of the Astronauts Memorial Foundation, and Kelvin Manning, Kennedy associate director, technical, will speak at the ceremony. This ceremony is open to the public. Media interested in attending should contact: Rebecca Shireman at RShireman@delawarenorth.com or 321-449-4273.
Johnson Space Center, Houston
NASA’s Johnson Space Center will hold a commemoration for employees at the Astronaut Memorial Grove to honor Apollo 1, Challenger and Columbia crews.
Stennis Space Center, Bay St. Louis, Mississippi
NASA’s Stennis Space Center will host a Day of Remembrance ceremony memorializing crew members of the Apollo 1, Challenger and Columbia missions, as well as members of the Stennis Space Center family lost in the past year. It will feature the laying of a ceremonial wreath in memory of those who have sacrificed in support of the nation’s space program.
Marshall Space Flight Center, Huntsville, Alabama
NASA’s Marshall Space Flight Center will observe Day of Remembrance with a candle-lighting ceremony for employees at 9 a.m. CST. Marshall Associate Director Steve Miley and former astronaut Jan Davis will offer remarks. Media interested in attending should contact Janet Sudnik at 256-544-0034 or firstname.lastname@example.org no later than 4 p.m. CST, Wednesday, Jan. 29.
#NASA; #ContractAwarded; #StingerGhaffarianTechnologies
Washington, Jan 22 (Canadian-Media): Stinger Ghaffarian Technologies, LLC, a KBRwyle business unit, of Greenbelt, Maryland has been selected by NASA for a contract for intelligent systems research and development support services at the agency's Ames Research Center in Moffett Field, California, NASA news release said.
This is a cost-plus-fixed-fee (CPFF) hybrid contract consisting of firm-fixed-price (FFP) contract line item numbers (CLINs) for phase-in and core management requirements; and CPFF or FFP CLINs for core technical and indefinite-delivery/indefinite-quantity requirements. It will begin on March 15 with a 60-day phase-in period followed by a two-year base period and three two-year options. The contract has a maximum value of $400 million.
The contractor will provide resources and technical expertise to support the Intelligent Systems Division on scientific research, technologies and applications development in a variety of research domains and infusion of advanced information systems technology on NASA missions and other projects within the federal government.
#NASA; #SpaceX; #CrewDragonSpacecraft; #Falcon9; #ISS; NASACommercialCrewProgram
Washington, Jan 19 (Canadian-Media): NASA and SpaceX completed a launch escape demonstration of the company’s Crew Dragon spacecraft and Falcon 9 rocket Sunday. This was the final major flight test of the spacecraft before it begins carrying astronauts to the International Space Station (ISS) under NASA’s Commercial Crew Program, NASA news reports said.
NASA and SpaceX completed a launch escape demonstration of the company’s Crew Dragon spacecraft and Falcon 9 rocket on Jan. 19, 2020. The test began at 10:30 a.m. EST with liftoff from Launch Complex 39A at NASA’s Kennedy Space Center in Florida on a mission to show the spacecraft’s capability to safely separate from the rocket in the unlikely event of an inflight emergency. Credits: NASA Television
The launch escape test began at 10:30 a.m. EST with liftoff from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida on a mission to show the spacecraft’s capability to safely separate from the rocket in the unlikely event of an inflight emergency.
“This critical flight test puts us on the cusp of returning the capability to launch astronauts in American spacecraft on American rockets from American soil,” said NASA Administrator Jim Bridenstine. “We are thrilled with the progress NASA’s Commercial Crew Program is making and look forward to the next milestone for Crew Dragon.”
As part of the test, SpaceX configured Crew Dragon to trigger a launch escape about 1.5 minutes after liftoff. All major functions were executed, including separation, engine firings, parachute deployment and landing. Crew Dragon splashed down at 10:38 a.m. just off the Florida coast in the Atlantic Ocean.
“As far as we can tell thus far, it’s a picture perfect mission. It went as well as one can possibly expect," said Elon Musk, Chief Engineer at SpaceX. “This is a reflection of the dedication and hard work of the SpaceX and NASA teams to achieve this goal. Obviously, I’m super fired up. This is great.”
Teams of personnel from SpaceX and the U.S. Air Force 45th Operations Group's Detachment-3 out of Patrick Air Force Base will recover the spacecraft for return to SpaceX facilities in Florida and begin the recovery effort of the Falcon 9, which broke apart as planned.
“The past few days have been an incredible experience for us,” said astronaut Doug Hurley. “We started with a full dress rehearsal of what Bob and I will do for our mission. Today, we watched the demonstration of a system that we hope to never use, but can save lives if we ever do. It took a lot of work between NASA and SpaceX to get to this point, and we can’t wait to take a ride to the space station soon.”
Prior to the flight test, teams completed launch day procedures for the first crewed flight test, from suit-up to launch pad operations. The joint teams now will begin the full data reviews that need to be completed prior to NASA astronauts flying the system during SpaceX’s Demo-2 mission.
NASA’s Commercial Crew Program is working with the American aerospace industry as companies develop and operate a new generation of spacecraft and launch systems capable of carrying crews to low-Earth orbit and the International Space Station. Commercial human space transportation to and from the station will provide expanded utility, additional research time and broader opportunities for discovery on the orbiting laboratory. The program also has the benefit of facilitating and promoting for America a vibrant economy in low-Earth orbit.
#Astronomy; #BlackHole; #FourNewDiscoveries; #BinaryStars
California (U.S.), Jan 18 (Canadian-Media): Unusual objects that look like gas and behave like stars, said the astronomers, have been spotted near our galaxy’s enormous black hole, media reports said.
Closely orbiting a supermassive black hole called Sagittarius A* located some 26,000 light years away from Earth, four new discoveries have been found.
Scientists have been intrigued with this, along with G1 and G2, which were found in 2005 and 2014 respectively, because they seem to be compact most of the time but stretch out as they get closer to the black hole during their orbit.
These orbits are also a much longer than the 365 days Earth takes to move around our sun, ranging from about 100 to 1,000 years.
These four new discoveries had been named as G3, G4, G5 and G6 by the researchers at the University of California, Los Angeles.
The group explained its belief in the Nature journal, that all six were once binary stars – a pair of stars which orbit each other – later merging as one due to the powerful gravitational force of black hole.
Co-author Andrea Ghez said that this merging process is not done overnight and that it takes more than one million years to complete.
“Mergers of stars may be happening in the universe more often than we thought, and likely are quite common,” she explained.
“Black holes may be driving binary stars to merge. It’s possible that many of the stars we’ve been watching and not understanding may be the end product of mergers that are calm now.
“We are learning how galaxies and black holes evolve. The way binary stars interact with each other and with the black hole is very different from how single stars interact with other single stars and with the black hole.”
Other potential objects that may be part of the same family are already being looked into by the team.
The research will help shine a light on what is happening in the majority of galaxies in our universe, says the team, though Earth is quite a distance from the action, “in the suburbs compared to the centre of the galaxy”, Ms Ghez added.
#NASA; #CommercialCrewProgram, #CommercialSpace, #KennedySpaceCenter; #SpaceXCrewDragonLaunch
Washington, Jan 15 (Canadian-Media): NASA will provide coverage of the upcoming pre-launch and launch activities for the SpaceX Crew Dragon launch escape demonstration, as part of the agency’s Commercial Crew Program, which is working with U.S. companies to launch American astronauts on American rockets and spacecraft from American soil, NASA news release said.
NASA and SpaceX are targeting 8 a.m. EST Saturday, Jan. 18, for launch of the company’s In-Flight Abort Test, which will demonstrate Crew Dragon’s ability to safely escape the Falcon 9 rocket in the event of a failure during launch. The abort test has a four-hour launch window.
The test launch, as well as other activities leading up to the test, will air on NASA Television and the agency’s website.
The SpaceX Crew Dragon will launch from historic Launch Complex 39A at NASA’s Kennedy Space Center in Florida. SpaceX will intentionally trigger Crew Dragon to perform the launch escape prior to 1 minute, 30 seconds into flight. Falcon 9 is expected to aerodynamically break up offshore over the Atlantic Ocean. The spacecraft is planned to land under parachutes offshore in the ocean.
Full coverage is as follows. All times are EST:
Friday, Jan. 17
Saturday, Jan. 18
The deadline for media to apply for accreditation for this launch has passed, but more information about media accreditation is available by emailing email@example.com.
The goal of NASA’s Commercial Crew Program is safe, reliable and cost-effective transportation to and from the International Space Station, which could allow for additional research time and increase the opportunity for discovery aboard humanity’s orbiting testbed for exploration.
#NASA; #11NewAstronauts; #LunarExploration; #SpaceWalking; #Robotics; #RussianLanguage; #T-38JetProficiency
Washington, Jan 10 (Canadian-Media): NASA welcomed 11 new astronauts to its ranks Friday, increasing the number of those eligible for spaceflight assignments that will expand humanity’s horizons in space for generations to come, NASA reports said.
NASA's new class of astronauts – the first to graduate since the agency announced its Artemis program – appear on stage during their graduation ceremony at the agency’s Johnson Space Center in Houston on Jan. 10, 2020. The class includes 11 NASA astronauts, as well as two Canadian Space Agency (CSA) astronauts, selected in 2017. They will join the active astronaut corps, beginning careers in exploration that may take them to the International Space Station, on missions to the Moon under the Artemis program, or someday, Mars. Pictured from left are: Kayla Barron of NASA, Zena Cardman of NASA, Raja Chari of NASA, Matthew Dominick of NASA, Bob Hines of NASA, Warren Hoburg of NASA, Jonny Kim of NASA, Joshua Kutryk of CSA, Jasmin Moghbeli of NASA, Loral O’Hara of NASA, Jessica Watkins of NASA, Jennifer Sidey-Gibbons of CSA, and Frank Rubio of NASA. Credits: NASA
The new astronauts successfully completed more than two years of required basic training and are the first to graduate since the agency announced its Artemis program.
The new graduates may be assigned to missions destined for the International Space Station, the Moon, and ultimately, Mars. With a goal of sustainable lunar exploration later this decade, NASA will send the first woman and next man to the surface on the Moon by 2024. Additional lunar missions are planned once a year thereafter and human exploration of Mars is targeted for the mid-2030s.
“These individuals represent the best of America, and what an incredible time for them to join our astronaut corps,” said NASA Administrator Jim Bridenstine at the agency’s Johnson Space Center in Houston where the graduation ceremony took place. “2020 will mark the return of launching American astronauts on American rockets from American soil, and will be an important year of progress for our Artemis program and missions to the Moon and beyond.”
During Friday’s ceremony, each new astronaut received a silver pin, a tradition dating back to the Mercury 7 astronauts, who were selected in 1959. They will receive a gold pin once they complete their first spaceflights.
This was the first public graduation ceremony for astronauts the agency has ever hosted, and Sens. John Cornyn and Ted Cruz of Texas were among the speakers at the event.
“For generations, the United States has been the world leader in space exploration, and Johnson Space Center will always be both the heart and home of human spaceflight activity,” said Cornyn. “I have no doubt the newly minted astronauts will add to that history and accomplish incredible things.”
Selected for training in 2017, the NASA astronaut candidates were chosen from a record-setting pool of more than 18,000 applicants.
“I congratulate these exceptional men and women on being the first graduating class of the Artemis program,” Cruz said. “They are the pioneers of the final frontier whose work will help fortify America's leadership in space for generations to come. I am excited for the opportunities ahead of them, including landing the first woman ever on the surface of the Moon, and having the first boots to step on Mars.”
Including the current class, NASA now has 48 active astronauts in its corps. NASA is also considering plans to open the application process this spring for the next class of astronaut candidates.
Training alongside the NASA astronaut candidates for the past two years were two Canadian Space Agency (CSA) astronauts who also participated in the graduation ceremony.
NASA’s newest astronauts are:
CSA’s newest astronauts are:
Astronaut candidate training for the new graduates included instruction, practice, and testing in spacewalking, robotics, International Space Station systems, T-38 jet proficiency, and Russian language. As astronauts, they will help develop spacecraft, support the teams currently in space and ultimately join the ranks of only about 500 people who have had the honor of going into space. NASA continues its work aboard the space station, which, in November, will celebrate 20 consecutive years of human occupation. The agency also is on the verge of launching astronauts again from American soil aboard American commercial spacecraft, and is preparing to send humans to the Moon as part of the Artemis program.
#NASA; #VertexAerospaceLLCOfMadison; #ArmstrongFlightResearchCenter
Washington, Jan 10 (Canadian-Media): NASA has awarded a contract to Vertex Aerospace LLC of Madison, Mississippi, for aircraft operations support at the agency’s Armstrong Flight Research Center in Edwards, California, and other NASA centers, as needed, NASA reports said.
NASA. Courtesy of NASA
The five-year, indefinite-delivery/indefinite-quantity contract has a value of $150 million and begins March 1.
Vertex will support all NASA-assigned aircraft operations, including maintenance, modification, and flight line operations.
#UniverseEmergedFromAPeriodofDarkness; #EGS77; reionization
Arizona (U.S.), Jan 9 (Canadian-Media): About 13 billion years ago, the universe emerged from a period of darkness, ushering in a cosmic dawn. As galaxies lit up with stars, they changed the chemical composition of their surroundings, allowing light to shine clearly throughout the universe, astronomy.com/news reports said.
This illustration of the EGS77 galaxy group shows the galaxies surrounded by overlapping bubbles of ionized hydrogen. Credit: NASA, ESA and V. Tilvi (ASU)
Looking in on that period is difficult. But, with telescopes that can peer billions of light-years away — and therefore back billions of years in time — scientists are getting a better idea of what the universe’s early days looked like.
In research highlighted Sunday at the 235th meeting of the American Astronomical Society, astronomers led by Vithal Tilvi at Arizona State University have spotted the most distant group of galaxies ever found. These young, bright objects are in the act of clearing away the fog of the early universe, showing astronomers just how the transition from darkness to light came about.
The work has been submitted to The Astrophysical Journal and is available on the preprint website arXiv.
Clearing the way
During the universe’s so-called “dark ages,” which began about half a billion years after the Big Bang, the abundant hydrogen that fills the cosmos was neutral (containing a proton and electron).
Neutral hydrogen scatters light like headlights in fog, so a universe filled with it is difficult to peer through. As the first galaxies formed stars, those young, bright suns began to emit energetic light. Their light ionized the hydrogen around them, knocking away electrons. Ionized hydrogen no longer scatters light, so by about one billion years after the Big Bang the fog had been cleared and light could travel freely.
“It’s somewhat akin to a frozen lake melting in the spring: The material is there, it’s the same set of atoms, but they’ve changed their physical conditions,” said team member James Rhoads of NASA’s Goddard Space Flight Center, during a press conference. “They’ve changed their properties in a way that hasn’t gone back in the subsequent 13 billion years."
Although astronomers have made progress in understanding this transition, called reionization, they have yet to decipher how exactly it occurred.
According to simulations, early galaxies ionized their environment in bubbles that ballooned and connected until the entire universe had been ionized. But those simulations offer several possible ways that reionization could have progressed.
To find out which scenario is correct, the team used the National Optical Astronomy Observatory’s Extremely Wide Field Infrared Imager, or NEWFIRM, on the 4-meter Mayall Telescope on Kitt Peak to search for a specific wavelength of light. Called Lyman-alpha, it is produced by young galaxies and stars. Although the light is emitted in ultraviolet wavelengths, it has been redshifted, or stretched, over time. Astronomers today must search for it as infrared light. And any early galaxies that popped up in the survey must have already ionized enough of their surroundings to let their Lyman-alpha light shine through, rather than scattering away.
The team spotted three distant galaxies that matched what they were looking for. Together, they form a galaxy group called EGS77. It is the most distant group of galaxies ever seen. Because looking at faraway galaxies is like looking back in time, astronomers are seeing EGS77 as it appeared about 680 million years after the Big Bang, when the universe was just 5 percent its current age.
Each galaxy is blowing a bubble of ionized hydrogen about 2 to 3 million light-years across, which is large enough that light can escape freely from the region.
What’s more, the bubbles are so big that they overlap, creating a larger, single region of space filled with ionized hydrogen around the group.
EGS77 is the first galaxy group caught in the process of reionization. The finding opens the door to a better understanding of this vital yet difficult-to-see transition in the early universe.
“Reionization was the last time that anything interesting happened in the life of a typical hydrogen atom, and it’s important to understand that history,” Rhoads said. “And if you look at how many galaxies there are where you see Lyman-alpha, you can start to do a census of what part of the universe must be ionized. So, what we do by doing this at different epochs of cosmic history is to map out the progress of reionization.”
That will ultimately help astronomers reveal exactly how the first stars and galaxies turned on, and with their light forever changed the cosmos.