Reentry data will help improve prediction models

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Reentry data will help improve prediction models

23 October 2015

A rare reentry of a suspected rocket body from a very high orbit next month offers an excellent opportunity to gather data to improve our knowledge of how objects interact with Earth’s atmosphere.

The expected 13 November reentry of what is likely to be a rocket body poses very little risk to anyone but could help scientists improve our understanding of how any object – man-made or natural – interacts with Earth’s atmosphere.

Returning to Earth

Observing and studying the reentry will help improve orbital models and reentry prediction tools, and can be used by scientists studying near-Earth objects (NEOs), such as natural asteroids, or the orbital decay of artificial objects such as satellites.

It was discovered by the Catalina Sky Survey in 2013 and has been observed several times since then by the same team, who have been sharing their data via the US-based Minor Planet Centre (MPC), the International Astronomical Union’s official repository for such observations.

Man-made origins

As confirmed by experts at ESA's NEO Coordination Centre (NEOCC), ESRIN, Italy, the object, dubbed WT1190F, is thought to be a discarded rocket body; it is orbiting Earth every three weeks in a highly ‘eccentric’ – that is, non-circular – orbit.

“NEO experts have used observational data to estimate the object’s density, which turns out to be much less than that of the solid rocky material that comprises many asteroids,” says Detlef Koschny, responsible for NEO activities at ESA’s Space Situational Awareness (SSA) programme office.

Detecting space hazards

“This density is in fact compatible with the object being a hollow shell, such as the spent upper stage of a rocket body or part of a stage.”

Forecast reentry next month

It is now predicted to reenter Earth's atmosphere in a few weeks, around 06:19 GMT (11:49 local; 07:19 CET) on 13 November 2015.

“The object is quite small, at most a couple of metres in diameter, and a significant fraction if not all of it can be expected to completely burn up in the atmosphere,” says Tim Flohrer, from ESA’s Space Debris Office at the ESOC operations centre in Darmstadt, Germany.

Whatever is left is expected to fall into the ocean about 100 km off the southern coast of Sri Lanka. Its mass is not sufficient to cause any risk to the area, but the show will still be spectacular, since for a few seconds the object will become quite bright in the mid-day sky.

Tim says this object is rather special as it is likely man-made, but was discovered by an NEO monitoring system and its orbit has many similarities with an NEO orbit.

This enables ESA experts to predict the impact time and location quite precisely, well in advance, which is usually not possible in comparison with reentering space-debris objects.

The more observations, teh better

During the next few weeks, the NEOCC will implement observational campaigns to collect as much data as possible on this object, explains Marco Micheli, as astronomer working at the NEOCC.

“The first goal will be to better understand the reentry of satellites and debris from highly eccentric orbits,” he says.

“Second, it provides an ideal opportunity to test our readiness for any possible future atmospheric entry events involving an asteroid, since the components of this scenario, from discovery to impact, are all very similar.”

Astronomers who may wish to observe the object are welcome to contact ESA’s NEOCC for further information.

About Space Situational Awareness

The objective of ESA’s SSA programme is to support Europe's independent utilisation of, and access to, space through the provision of timely and accurate information and data regarding the space environment, especially regarding hazards to infrastructure in orbit and on the ground. In general, these hazards stem from possible collisions between objects in orbit, harmful space weather and potential strikes by natural objects, such as asteroids, that cross Earth’s orbit.

More information via http://www.esa.int/ssa

Editor's note: Text updated 23 October to remove map of forecast reentry location, as this is still uncertain, and to correct the citation for Tim Flohrer.

Images, Text, Credits: ESA/B. Bolin, R. Jedicke, M. Micheli/CC BY-SA IGO 3.0.

Best regards, Orbiter.ch

A Hubble View of Starburst Galaxy Messier 94

NASA - Hubble Space Telescope patch.

Oct. 23, 2015

his image shows the galaxy Messier 94, which lies in the small northern constellation of the Hunting Dogs, about 16 million light-years away.

Within the bright ring or starburst ring around Messier 94, new stars are forming at a high rate and many young, bright stars are present within it.

The cause of this peculiarly shaped star-forming region is likely a pressure wave going outwards from the galactic center, compressing the gas and dust in the outer region. The compression of material means the gas starts to collapse into denser clouds. Inside these dense clouds, gravity pulls the gas and dust together until temperature and pressure are high enough for stars to be born.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, in Washington.

For images and more information about Hubble, visit: http://www.nasa.gov/hubble and http://hubblesite.org/ and http://www.spacetelescope.org/

Text credit: European Space Agency/Image credit: ESA/NASA/Ashley Morrow.

Greetings, Orbiter.ch

Astronauts Tailor Spacesuits as Crew Explores Human Research

ISS - Expedition 45 Mission patch.

October 22, 2015

The crew started their day checking out Cubesat gear and researching a wide variety of science to benefit humanity on and off Earth. Later, two astronauts tried on their spacesuits to ensure a good fit before next week’s spacewalk.

Image above: A U.S. spacesuit is pictured inside the Quest joint airlock. Image Credit: NASA.

Commander Scott Kelly and Flight Engineer Kjell Lindgren were in the Kibo lab module Thursday morning inspecting and photographing a small satellite deployer mechanism. The mechanism failed to eject a pair of Cubesats two weeks ago and payload controllers are troubleshooting the issue.

During the afternoon, the duo got back together inside the U.S. Quest airlock and tried on the spacesuits they will wear on spacewalks scheduled for Oct. 28 and Nov. 6. They were assisted inside the airlock by Japanese astronaut Kimiya Yui and cosmonaut Sergey Volkov. Yui will guide the spacewalkers and operate the 57.7 foot Canadarm2 robotic arm during the spacewalks.

Image above: Expedition 45 crew members Kimiya Yui, Kjell Lindgren and Sergey Volkov work inside the Quest airlock to get a pair of spacesuits ready for upcoming spacewalks. Image Credit: NASA TV.

The first spacewalk is set to last six-hours and 30-minutes after Kelly and Lindgren set their spacesuits to battery power. The duo will exit Quest to place a thermal cover over a dark matter detection experiment, lubricate the 57.7 foot Canadarm2 robotic and route power cables for a future docking port.

More human research took place today as the crew looked at brain adaptation and cognitive performance on the space station. The crew also explored sleep disturbances and changes in cardiac and respiratory behavior during long-term missions.

International Space Station (ISS). Image Credit: NASA

The entire crew still continued the work of on-orbit science, the primary purpose of the space station. Cosmonaut Mikhail Kornienko, along with Kelly and Lindgren performed cardiac scans with an ultrasound for the Ocular Health study. Japanese astronaut Kimiya Yui set up a mouse habitat inside the Cell Biology Experiment Facility.

Related links:

Brain adaptation: http://www.nasa.gov/mission_pages/station/research/experiments/1007.html

Cognitive performance: http://www.nasa.gov/mission_pages/station/research/experiments/1256.html

Sleep disturbances: http://www.nasa.gov/mission_pages/station/research/experiments/1802.html

Cardiac and respiratory behavior: http://www.energia.ru/en/iss/researches/human/19.html

Ocular Health study: http://www.nasa.gov/mission_pages/station/research/experiments/204.html

Cell Biology Experiment Facility: http://www.nasa.gov/mission_pages/station/research/experiments/342.html

Expedition 45: https://blogs.nasa.gov/spacestation/category/expedition-45/

For more information about the International Space Station (ISS), visit: https://www.nasa.gov/mission_pages/station/main/

Images (mentioned), Text, Credits: NASA/Mark Garcia.

Best regards, Orbiter.ch

NASA Takes Lasercom a Step Forward

NASA - Lunar Laser Communication Demonstration (LLCD) logo.

Oct. 22, 2015

A NASA-developed laser communication (lasercom) system made headlines in 2013 when it demonstrated record-breaking data download and upload speeds to the moon. Now, a NASA optical physicist says he can match those speeds — plus provide never-before-achieved, highly precise distance and speed measurements -- all from the same relatively small package.

Called the Space Optical Communication and Navigation System, the breadboard technology is made up of commercially available components simulating both ground and space terminals. It recently demonstrated in laboratory testing that it could provide micrometer-level distance and speed measurements over a 622 megabits-per-second (Mbps) laser communication link.

Advances in Communications, Navigation and Science

“Combined with the large communication bandwidth, high-precision ranging over an optical communication network will bring about significant advances in navigation and communications, to say nothing of science gathering, notably in the area of geodesy,” said technology developer Guan Yang, an optical physicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. (Geodesy is the science of measuring variations in Earth’s gravitational field caused by changing land mass.) And because of its diminutive size, “it also will enable use on CubeSats,” an increasingly popular spacecraft bus that typically is no larger than a shoebox.

The ground-based test was similar to one carried out in late 2013 aboard another Goddard-developed lasercom experiment hosted on NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE).

Image above: Illustration of The Lunar Laser Communication Demonstration (LLCD) is NASA's first high-rate, two-way, space laser communication demonstration. Image Credits: NASA/GSFC.

During the LADEE demonstration, the Lunar Laser Communication Demonstration (LLCD) experiment downloaded and uploaded test data to and from lunar orbit at 622 megabits per second (Mbps) and 20 Mbps, respectively, proving that it could operate as well as any NASA radio system. Mission operators also used LLCD’s lasercom system to download LADEE’s stored science and spacecraft data. It took just four minutes to download the data, a feat that would have taken several days if using only LADEE’s onboard radio system at 50 kilobits per second.

But before the LLCD mission could break the data-transmission records, it needed to know the speed of the LADEE spacecraft as it orbited the moon as well as its distance from the LLCD ground terminals. This required that the high-frequency laser beam that carried the embedded data also obtained very precise distance and speed measurements.

It succeeded. LLCD’s instrument gathered velocity measurements with a precision better than 10 millimeters per second; its position calculations were precise to within 12 millimeters, the best measurements ever recorded over lunar distances.

Image above: Guan Yang (right) and his research associate, Wei Lu, pose in front of the lasercom breadboard they created to demonstrate high data-rate download and uplink speeds as well as highly precise distance and speed measurements all from the same, relatively small package. Image Credits: NASA/W. Hrybyk.

Besting LLCD

Yang’s new miniaturized lasercom transceiver, however, improved upon LLCD’s precision by several orders of magnitude in laboratory testing. In addition to transmitting data at LLCD’s record-breaking rate of 622 Mbps, it measured speed within a precision of less than 10 micrometers per second and distances within 20 micrometers.

The system achieved these unprecedented precise measurements by incorporating a Doppler frequency — which can be likened to an ambulance siren that increases or decreases in pitch as the vehicle travels closer or farther away — enabled by a highly specialized computing algorithm, called the Fast Fourier Transform.

“When you’re trying to predict where something is, one of the issues is eliminating measurement errors,” said Dennis Woodfork, a Goddard assistant chief for technology specializing in navigation and communication technologies. “If errors build too much, you will lose position, and therefore, you won’t know where the spacecraft will be in the future. Guan’s measurements are at least an order-of-magnitude better. He got great ranging.”

Yang agrees. “If you can measure that precisely, you can easily use it for navigation,” he said. He envisions its use on a constellation of smallsats flying in an exacting formation to get simultaneous, multi-point observations or as the navigational guide to carry out autonomous rendezvous and docking.

Science also could benefit, he said. Due to its precise pointing and micrometer-level, two-way ranging, he believes the technology is particularly ideal for geodesy, the science of measuring variations in Earth’s gravitational field. “This system opens a new way for to carry out all types of science missions,” Yang said.

Although pleased with the test results, Yang now wants to further improve the technology and ultimately fly it on a CubeSat. “The test proved the concept and precision in the lab. I’m now talking with the science community to find an application. We are targeting a CubeSat opportunity.”

Related links:

Lasercom experiment: http://www.nasa.gov/press/2013/october/nasa-laser-communication-system-sets-record-with-data-transmissions-to-and-from/#.VfrTQXu07OS

Lunar Laser Communication Demonstration (LLCD): http://esc.gsfc.nasa.gov/267/271.html

For more Goddard technology news, go to https://gsfctechnology.gsfc.nasa.gov/newsletter/Current.pdf

For more information about LADEE, visit: http://www.nasa.gov/ladee

Images (mentioned), Text, Credits: NASA’s Goddard Space Flight Center/Lori Keesey/Lynn Jenner.

Greetings, Orbiter.ch

NASA Completes Critical Design Review for Space Launch System

NASA - Space Launch System (SLS) logo.

Oct. 22, 2015

For the first time in almost 40 years, a NASA human-rated rocket has completed all steps needed to clear a critical design review (CDR). The agency’s Space Launch System (SLS) is the first vehicle designed to meet the challenges of the journey to Mars and the first exploration class rocket since the Saturn V.

SLS will be the most powerful rocket ever built and, with the agency’s Orion spacecraft, will launch America into a new era of exploration to destinations beyond Earth’s orbit. The CDR provided a final look at the design and development of the integrated launch vehicle before full-scale fabrication begins.

Image above: Artist concept of the Block I configuration of NASA’s Space Launch System (SLS). The SLS Program has completed its critical design review, and the program has concluded that the core stage of the rocket will remain orange along with the Launch Vehicle Stage Adapter, which is the natural color of the insulation that will cover those elements. Image Credits: NASA.

“We’ve nailed down the design of SLS, we’ve successfully completed the first round of testing of the rocket’s engines and boosters, and all the major components for the first flight are now in production,” said Bill Hill, deputy associate administrator of NASA’s Exploration Systems Development Division. “There have been challenges, and there will be more ahead, but this review gives us confidence that we are on the right track for the first flight of SLS and using it to extend permanent human presence into deep space.”

The CDR examined the first of three configurations planned for the rocket, referred to as SLS Block 1. The Block I configuration will have a minimum 70-metric-ton (77-ton) lift capability and be powered by twin boosters and four RS-25 engines. The next planned upgrade of SLS, Block 1B, would use a more powerful exploration upper stage for more ambitious missions with a 105-metric-ton (115-ton) lift capacity. Block 2 will add a pair of advanced solid or liquid propellant boosters to provide a 130-metric-ton (143-ton) lift capacity. In each configuration, SLS will continue to use the same core stage and four RS-25 engines.

The SLS Program completed the review in July, in conjunction with a separate review by the Standing Review Board, which is composed of seasoned experts from NASA and industry who are independent of the program. Throughout the course of 11 weeks, 13 teams – made up of senior engineers and aerospace experts across the agency and industry – reviewed more than 1,000 SLS documents and more than 150 GB of data as part of the comprehensive assessment process at NASA’s Marshall Space Flight Center in Huntsville, Alabama, where SLS is managed for the agency.

The Standing Review Board reviewed and assessed the program’s readiness and confirmed the technical effort is on track to complete system development and meet performance requirements on budget and on schedule.

The program briefed the results of the review in October to the Agency Program Management Council, led by NASA Associate Administrator Robert Lightfoot, as the final step in the CDR process.

This review is the last of four reviews that examine concepts and designs. The next step for the program is design certification, which will take place in 2017 after manufacturing, integration and testing is complete. The design certification will compare the actual final product to the rocket’s design. The final review, the flight readiness review, will take place just prior to the 2018 flight readiness date.

SLS block 1 expanded view. Image Credits: NASA/MSFC

“This is a major step in the design and readiness of SLS,” said John Honeycutt, SLS program manager. “Our team has worked extremely hard, and we are moving forward with building this rocket. We are qualifying hardware, building structural test articles, and making real progress.”

Critical design reviews for the individual SLS elements of the core stage, boosters and engines were completed successfully as part of this milestone. Also as part of the CDR, the program concluded the core stage of the rocket and Launch Vehicle Stage Adapter will remain orange, the natural color of the insulation that will cover those elements, instead of painted white. The core stage, towering more than 200 feet tall and with a diameter of 27.6 feet, will carry cryogenic liquid hydrogen and liquid oxygen fuel for the rocket’s four RS-25 engines.

The integrated spacecraft and payloads are nearing completion on their CDR. Flight hardware currently is in production for every element. NASA is preparing for a second qualification test for the SLS boosters, and structural test articles for the core and upper stages of the rocket are either completed or currently in production. NASA also recently completed the first developmental test series on the RS-25 engines.

Related links:

ESD (Exploration Systems Development): http://www.nasa.gov/exploration/systems/index.html

Journey to Mars: http://www.nasa.gov/topics/journeytomars/index.html

Future program reviews will focus on SLS integration and flight readiness. For more information on SLS, visit: http://www.nasa.gov/sls

Images (mentioned), Text, Credits: NASA/Kathryn Hambleton/Marshall Space Flight Center/Shannon Ridinger/Karen Northon.

Best regards, Orbiter.ch

Last of Pluto’s Moons – Mysterious Kerberos – Revealed by New Horizons

NASA New Horizons Mission logo.

Oct. 22, 2015

Image above: Kerberos Revealed. This image of Kerberos was created by combining four individual Long Range Reconnaissance Imager (LORRI) pictures taken on July 14, approximately seven hours before New Horizons’ closest approach to Pluto, at a range of 245,600 miles (396,100 km) from Kerberos. The image was deconvolved to recover the highest possible spatial resolution and oversampled by a factor of eight to reduce pixilation effects. Kerberos appears to have a double-lobed shape, approximately 7.4 miles (12 kilometers) across in its long dimension and 2.8 miles (4.5 kilometers) in its shortest dimension. Image Credits: NASA/JHUAPL/SwRI.

Images of Pluto’s tiny moon Kerberos taken by NASA’s New Horizons spacecraft –and just sent back to Earth this week – complete the family portrait of Pluto’s moons.

Kerberos appears to be smaller than scientists expected and has a highly-reflective surface, counter to predictions prior to the Pluto flyby in July. “Once again, the Pluto system has surprised us,” said New Horizons Project Scientist Hal Weaver, of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The new data, downlinked from the New Horizons spacecraft on Oct. 20, show that Kerberos appears to have a double-lobed shape, with the larger lobe approximately 5 miles (8 kilometers) across and the smaller lobe approximately 3 miles (5 kilometers) across. Science team members speculate from its unusual shape that Kerberos could have been formed by the merger of two smaller objects. The reflectivity of Kerberos’ surface is similar to that of Pluto’s other small moons (approximately 50 percent) and strongly suggests Kerberos, like the others, is coated with relatively clean water ice.

Image above: Family Portrait of Pluto’s Moons: This composite image shows a sliver of Pluto’s large moon, Charon, and all four of Pluto’s small moons, as resolved by the Long Range Reconnaissance Imager (LORRI) on the New Horizons spacecraft. All the moons are displayed with a common intensity stretch and spatial scale (see scale bar). Charon is by far the largest of Pluto’s moons, with a diameter of 751 miles (1,212 kilometers). Nix and Hydra have comparable sizes, approximately 25 miles (40 kilometers) across in their longest dimension above. Kerberos and Styx are much smaller and have comparable sizes, roughly 6-7 miles (10-12 kilometers) across in their longest dimension. All four small moons have highly elongated shapes, a characteristic thought to be typical of small bodies in the Kuiper Belt. Image Credits: NASA/JHUAPL/SwRI.

Before the New Horizons encounter with Pluto, researchers had used Hubble Space Telescope images to “weigh” Kerberos by measuring its gravitational influence on its neighboring moons.  That influence was surprisingly strong, considering how faint Kerberos was. They theorized that Kerberos was relatively large and massive, appearing faint only because its surface was covered in dark material. But the small, bright-surfaced Kerberos--now revealed in these new images--shows that the idea was incorrect, for reasons that are not yet understood.

“Our predictions were nearly spot-on for the other small moons, but not for Kerberos,” said New Horizons co-investigator Mark Showalter, of the SETI Institute in Mountain View, California. The new results are expected to lead to a better understanding of Pluto’s fascinating satellite system.

New Horizons is part of NASA’s New Frontiers Program, managed by the agency’s Marshall Space Flight Center in Huntsville, Alabama.  APL designed, built, and operates the New Horizons spacecraft and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science mission, payload operations, and encounter science planning.

For more information about New Horizons mission, visit: http://www.nasa.gov/mission_pages/newhorizons/main/index.html

Images (mentioned), Text, Credits. NASA/Tricia Talbert.

Greetings, Orbiter.ch

Hubble Spies Big Bang Frontiers

ESA - Hubble Space Telescope logo.

Oct. 22, 2015

Hubble Frontier Fields view of MACSJ0416.1–2403

Observations by the NASA/ESA Hubble Space Telescope have taken advantage of gravitational lensing to reveal the largest sample of the faintest and earliest known galaxies in the Universe. Some of these galaxies formed just 600 million years after the Big Bang and are fainter than any other galaxy yet uncovered by Hubble. The team has determined, for the first time with some confidence, that these small galaxies were vital to creating the Universe that we see today.

An international team of astronomers, led by Hakim Atek of the Ecole Polytechnique Fédérale de Lausanne, Switzerland, has discovered over 250 tiny galaxies that existed only 600-900 million years after the Big Bang [1] — one of the largest samples of dwarf galaxies yet to be discovered at these epochs. The light from these galaxies took over 12 billion years to reach the telescope, allowing the astronomers to look back in time when the universe was still very young.

Hubble Frontier Fields view of MACSJ0717.5+3745

Although impressive, the number of galaxies found at this early epoch is not the team’s only remarkable breakthrough, as Johan Richard from the Observatoire de Lyon, France, points out, “The faintest galaxies detected in these Hubble observations are fainter than any other yet uncovered in the deepest Hubble observations.”

By looking at the light coming from the galaxies the team discovered that the accumulated light emitted by these galaxies could have played a major role in one of the most mysterious periods of the Universe’s early history — the epoch of reionisation. Reionisation started when the thick fog of hydrogen gas that cloaked the early Universe began to clear. Ultraviolet light was now able to travel over larger distances without being blocked and the Universe became transparent to ultraviolet light [2].

Hubble Frontier Fields view of Abell 2744

By observing the ultraviolet light from the galaxies found in this study the astronomers were able to calculate whether these were in fact some of the galaxies involved in the process. The team determined, for the first time with some confidence, that the smallest and most abundant of the galaxies in the study could be the major actors in keeping the Universe transparent. By doing so, they have established that the epoch of reionisation — which ends at the point when the Universe is fully transparent — came to a close about 700 million years after the Big Bang [3].

Lead author Atek explained, “If we took into account only the contributions from bright and massive galaxies, we found that these were insufficient to reionise the Universe. We also needed to add in the contribution of a more abundant population of faint dwarf galaxies.”

To make these discoveries, the team utilised the deepest images of gravitational lensing made so far in three galaxy clusters, which were taken as part of the Hubble Frontier Fields programme [4]. These clusters generate immense gravitational fields capable of magnifying the light from the faint galaxies that lie far behind the clusters themselves. This makes it possible to search for, and study, the first generation of galaxies in the Universe.

Hubble and the sunrise over Earth

Jean-Paul Kneib, co-author of the study from the Ecole Polytechnique Fédérale de Lausanne, Switzerland, explains, “Clusters in the Frontier Fields act as powerful natural telescopes and unveil these faint dwarf galaxies that would otherwise be invisible.”

Co-author of the study Mathilde Jauzac, from Durham University, UK, and the University of KwaZulu-Natal, South Africa, remarks on the significance of the discovery and Hubble’s role in it,“Hubble remains unrivalled in its ability to observe the most distant galaxies. The sheer depth of the Hubble Frontier Field data guarantees a very precise understanding of the cluster magnification effect, allowing us to make discoveries like these.”

These results highlight the impressive possibilities of the Frontier Fields programme with more galaxies, at even earlier time, likely to be revealed when Hubble peers at three more of these galaxy clusters in the near future.

Notes:

[1] The calculated redshift for these objects is between z = 6 and z = 8.

[2] Neutral hydrogen gas absorbs all the high-energy ultraviolet light emitted by hot young stars very efficiently. At the same time, the absorbed ultraviolet light ionises the hydrogen. The very low density ionised hydrogen gas filling the universe became fully transparent.The hot stars carve out transparent bubbles in the gas and once all these bubbles merge to fill all of space, reionisation is said to be complete and the Universe becomes transparent to ultraviolet light.

[3] This corresponds to a redshift of about z = 7.5.

[4] The Hubble Frontier Fields is a three-year, 840-orbit programme which will yield the deepest views of the Universe to date, combining the power of Hubble with the gravitational amplification of light around six different galaxy clusters to explore more distant regions of space than could otherwise be seen.

Notes for editors:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

More information:

This research was presented in a paper entitled “Are Ultra-faint Galaxies at z = 6−8 Responsible for Cosmic Reionization? Combined Constraints from the Hubble Frontier Fields Clusters And Parallels”, by H. Atek et al., to appear in the Astrophysical Journal.

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The international team of astronomers in this study consists of Hakim Atek (Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne, Switzerland ; Department of Astronomy, Yale University, USA), Johan Richard (CRAL, Observatoire de Lyon, France), Mathilde Jauzac (Institute for Computational Cosmology, Durham University, UK; Astrophysics and Cosmology Research Unit, University of KwaZulu-Natal, South Africa), Jean-Paul Kneib (Laboratoire d’Astrophysique, Ecole Polytechnique Fédérale de Lausanne, Switzerland; Aix Marseille Université, CNRS, LAM UMR 7326, France), Priyamvada Natarajan (Department of Astronomy, Yale University, USA), Marceau Limousin (Aix Marseille Université, CNRS, LAM UMR 7326, France), Daniel Schaerer (Observatoire de Genève, Switzerland; CNRS, IRAP, France), Eric Jullo (Aix Marseille Université, CNRS, LAM UMR 7326, France), Harald Ebeling (Institute for Astronomy, University of Hawaii, USA), Eiichi Egami (Steward Observatory, University of Arizona, USA), and Benjamin Clement (CRAL, Observatoire de Lyon, France).

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

Frontier Fields programme: http://frontierfields.org/

Link to science paper: http://www.spacetelescope.org/static/archives/releases/science_papers/heic1523a.pdf

Hubblecast 70: Peering around cosmic corners: http://www.spacetelescope.org/videos/hubblecast70a/

Images, Text, Video, Credits: NASA, ESA and the HST Frontier Fields team (STScI).

Greetings, Orbiter.ch