It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Friday, October 04, 2024
SPACE/COSMOLOGY
ULA successfully launches second Vulcan rocket after delays | A United Launch Alliance (ULA) Vulcan rocket launches on its second mission, Cert - 2, at 7:25 AM from Launch Complex 41 at the Cape Canaveral Space Force Station, Florida on Friday October 4, 2024. .Photo by Joe Marino/UPI | License Photo
Oct. 4 (UPI) -- United Launch Alliance sent its second Vulcan rocket into space on Friday morning after delays that took the launch back more than hour from its original time off the Florida coast.
The secret payload that ULA President and CEO Tory Bruno called "highly proprietary," took off from Complex 41 at the Cape Canaveral Space Force Station at about 7:25 a.m., EDT.
The ULA launch was initially set for about 6 a.m., EDT. However, 12 minutes before liftoff, launch conductor Dillon Rice told launch director Eric Richards that the launch team needed extra time "to complete operations." A new launch time was set for 6:30 a.m.
The launch clock was reset again less than two minutes before the new liftoff time and held past the second liftoff time. A third liftoff time was set once the issue was resolved.
Before then, officials reported that the weather remained optimal for launch and no technical issues were identified and needed to be addressed before blastoff.
This was the second ULA launch with a Vulcan rocket, which will launch a payload that will study conditions for future Centaur 5 demonstrations and experiments. ULA will be watching how Centaur 5 handles at low temperatures in space.
"We'll also have experiments attached to this inert payload that will help us understand how to extend the duration of the upper stage and what the limits, practical limits, to that might be in the future," Bruno said.
ULA launches second Vulcan rocket
A United Launch Alliance Vulcan rocket lifts off from Complex 41 at Cape Canaveral Space Force Station in Florida on October 4, 2024. Photo by Joe Marino/UPI | License Photo
Hera spacecraft to probe asteroid deflected by defence test
By AFP October 4, 2024 The asteroid Dimorphos was successfully deflected by humanity's first test of Earth's planetary defences - Copyright KCNA VIA KNS/AFP STR
Benedicte Rey and Daniel Lawler
Europe’s Hera probe is tentatively scheduled to launch Monday on a mission to inspect the damage a NASA spacecraft made when it smashed into an asteroid during the first test of Earth’s planetary defences.
In a scene that sounds straight out of science fiction, the spacecraft deliberately crashed into the pyramid-sized asteroid Dimorphos in 2022, roughly 11 million kilometres (6.8 million miles) from Earth.
The fridge-sized impactor used in the Double Asteroid Redirection Test (DART) successfully knocked the asteroid well off its course.
This demonstrated that the idea worked — humanity may no longer be powerless against potentially planet-killing asteroids that could approach in the future.
But much about the impact remains unknown, including how much damage was done and exactly what the asteroid was like before it was hit.
So the European Space Agency said it was sending Hera to the asteroid to conduct a “crime scene investigation” in the hopes of learning how Earth can best fend off asteroids that pose a threat.
The spacecraft is scheduled to blast off on a SpaceX Falcon 9 rocket from Cape Canaveral in the US state of Florida on Monday.
– ‘Anomaly’ could delay launch –
However an “anomaly” involving a Falcon 9 rocket during the launch of SpaceX’s Crew-9 astronaut mission on Saturday could potentially delay the launch date, the ESA’s Hera project manager Ian Carnelli said at a press conference.
The ESA is hoping to receive approval by Sunday from the US Federal Aviation Administration, NASA and SpaceX, Carnelli said.
The launch window for the mission will remain open until October 27.
Once launched, Hera is planned to fly past Mars next year and then arrive near Dimorphos in December 2026 to begin its six-month investigation.
An asteroid wider than a kilometre (0.6 miles) — which could trigger a global catastrophe on a scale that wiped out the dinosaurs — is estimated to strike Earth every 500,000 years or so.
An asteroid around 140 metres (460 feet) wide — which is a little smaller than Dimorphos but could still take out a major city — hits our home planet around every 20,000 years.
Most of these celestial objects come from the asteroid belt between Mars and Jupiter. Almost all those bigger than a kilometre wide are known to scientists, and none are expected to threaten Earth in the next century.
There are also no known 140-metre asteroids on a collision course with Earth — but only 40 percent of those space rocks are believed to have been identified.
Although asteroids are one of the least likely natural disasters to strike the planet, people now have the “advantage of being able to protect ourselves against them”, the Hera mission’s principal investigator Patrick Michel said.
– Loose rubble ‘defies intuition’ –
Dimorphos, which is actually a moonlet orbiting its big brother Didymos, never posed a threat to Earth.
After DART’s impact, Dimorphos shed material to the point where its orbit around Didymos was shortened by 33 minutes — proof that it was successfully deflected.
Analysis of the DART mission has suggested that rather than being a single hard rock, Dimorphos was more a loose pile of rubble held together by gravity.
“The consequence of this is that, instead of making a crater” on Dimorphos, DART may have “completely deformed” the asteroid, Michel said.
But there are other possibilities, he said, adding that the behaviour of these low-gravity objects is little understood and “defies intuition”.
The 363-million-euro ($400 million) mission will be equipped with 12 scientific instruments and two nanosatellites.
The Juventas nanosatellite will aim to land on Dimorphos, which would be a first on such a small asteroid. It will use radar to probe deep inside the asteroid and a gravimeter to measure its gravity.
From farther away, the Milani nanosatellite will use cameras and other instruments to study the asteroid’s composition and assess DART’s impact.
Once its job is done, the team on the ground hopes that Hera can land gently on Dimorphos or Didymos, where it will spend the rest of its days.
NASA’s LRO: Lunar ice deposits are widespread
NASA/Goddard Space Flight Center
image:
This illustration shows the distribution of permanently shadowed regions (in blue) on the Moon poleward of 80 degrees South latitude. They are superimposed on a digital elevation map of the lunar surface (grey) from the Lunar Orbiter Laser Altimeter instrument on board NASA’s Lunar Reconnaissance Orbiter spacecraft.
Deposits of ice in lunar dust and rock (regolith) are more extensive than previously thought, according to a new analysis of data from NASA’s LRO (Lunar Reconnaissance Orbiter) mission. Ice would be a valuable resource for future lunar expeditions. Water could be used for radiation protection and supporting human explorers, or broken into its hydrogen and oxygen components to make rocket fuel, energy, and breathable air.
Prior studies found signs of ice in the larger permanently shadowed regions (PSRs) near the lunar South Pole, including areas within Cabeus, Haworth, Shoemaker and Faustini craters. In the new work, “We find that there is widespread evidence of water ice within PSRs outside the South Pole, towards at least 77 degrees south latitude,” said Dr. Timothy P. McClanahan of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and lead author of a paper on this research published October 2 in the Planetary Science Journal.
The study further aids lunar mission planners by providing maps and identifying the surface characteristics that show where ice is likely and less likely to be found, with evidence for why that should be. “Our model and analysis show that greatest ice concentrations are expected to occur near the PSRs’ coldest locations below 75 Kelvin (-198°C or -325°F) and near the base of the PSRs’ poleward-facing slopes,” said McClanahan.
“We can’t accurately determine the volume of the PSRs’ ice deposits or identify if they might be buried under a dry layer of regolith. However, we expect that for each surface 1.2 square yards (square meter) residing over these deposits there should be at least about five more quarts (five more liters) of ice within the surface top 3.3 feet (meter), as compared to their surrounding areas,” said McClanahan. The study also mapped where fewer, smaller, or lower-concentration ice deposits would be expected, occurring primarily towards warmer, periodically illuminated areas.
Ice could become implanted in lunar regolith through comet and meteor impacts, released as vapor (gas) from the lunar interior, or be formed by chemical reactions between hydrogen in the solar wind and oxygen in the regolith. PSRs typically occur in topographic depressions near the lunar poles. Because of the low Sun angle, these areas haven’t seen sunlight for up to billions of years, so are perpetually in extreme cold. Ice molecules are thought to be repeatedly dislodged from the regolith by meteorites, space radiation, or sunlight and travel across the lunar surface until they land in a PSR where they are entrapped by extreme cold. The PSR’s continuously cold surfaces can preserve ice molecules near the surface for perhaps billions of years, where they may accumulate into a deposit that is rich enough to mine. Ice is thought to be quickly lost on surfaces that are exposed to direct sunlight, which precludes their accumulations.
The team used LRO’s Lunar Exploration Neutron Detector (LEND) instrument to detect signs of ice deposits by measuring moderate-energy, “epithermal” neutrons. Specifically, the team used LEND’s Collimated Sensor for Epithermal Neutrons (CSETN) that has a fixed 18.6-mile (30-kilometer) diameter field-of-view. Neutrons are created by high-energy galactic cosmic rays that come from powerful deep-space events such as exploding stars, that impact the lunar surface, break up regolith atoms, and scatter subatomic particles called neutrons. The neutrons, which can originate from up to about a 3.3-foot (meter’s) depth, ping-pong their way through the regolith, running into other atoms. Some get directed into space, where they can be detected by LEND. Since hydrogen is about the same mass as a neutron, a collision with hydrogen causes the neutron to lose relatively more energy than a collision with most common regolith elements. So, where hydrogen is present in regolith, its concentration creates a corresponding reduction in the observed number of moderate-energy neutrons.
“We hypothesized that if all PSRs have the same hydrogen concentration, then CSETN should proportionally detect their hydrogen concentrations as a function of their areas. So, more hydrogen should be observed towards the larger-area PSRs,” said McClanahan.
The model was developed from a theoretical study that demonstrated how similarly hydrogen-enhanced PSRs would be detected by CSETNs fixed-area field-of-view. The correlation was demonstrated using the neutron emissions from 502 PSRs with areas ranging from 1.5 square miles (4 km2) to 417 square miles (1079 km2) that contrasted against their surrounding less hydrogen-enhanced areas. The correlation was expectedly weak for the small PSRs but increased towards the larger-area PSRs.
The research was sponsored by the LRO project science team, NASA’s Goddard Space Flight Center’s Artificial Intelligence Working Group, and NASA grant award number 80GSFC21M0002. The study was conducted using NASA's LRO Diviner radiometer and Lunar Orbiter Laser Altimeter instruments. The LEND instrument was developed by the Russian Space Agency, Roscosmos by its Space Research Institute (IKI). LEND was integrated to the LRO spacecraft at the NASA Goddard Space Flight Center. LRO is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, for the Science Mission Directorate at NASA Headquarters in Washington.
Evidence for Widespread Hydrogen Sequestration within the Moon's South Pole Cold Traps
Article Publication Date
2-Oct-2024
A new era of solar observation
International team produces global maps of coronal magnetic field
National Center for Atmospheric Research/University Corporation for Atmospheric Research
image:
Illustration of the global coronal magnetic field as the Sun rotates. The background is the solar corona observed in extreme-ultraviolet waveband, with global coronal magnetic field maps measured at different time overlapped on top of it.
For the first time, scientists have taken near-daily measurements of the Sun’s global coronal magnetic field, a region of the Sun that has only been observed irregularly in the past. The resulting observations are providing valuable insights into the processes that drive the intense solar storms that impact fundamental technologies, and thus lives and livelihoods, here on Earth.
An analysis of the data, collected over eight months by an instrument called the Upgraded Coronal Multi-channel Polarimeter (UCoMP), is published today in Science.
The solar magnetic field is the primary driver of solar storms, which can pose threats to power grids, communication systems, and in-space technologies like GPS. However, our ability to understand how the magnetic field builds up energy and erupts has been limited by the challenge of observing it in the solar corona, the Sun’s upper atmosphere.
Measuring the magnetism of the region through standard polarimetric methods typically requires large, expensive equipment that to date has only been able to study small segments of the corona. However, the combined use of coronal seismology and UCoMP observations makes it possible for researchers to produce consistent and comprehensive views of the magnetic field of the global corona — the whole-Sun view one sees during a solar eclipse.
“Global mapping of the coronal magnetic field has been a big missing part in the study of the Sun,” said Zihao Yang, lead author who pursued this research as a PhD graduate at Peking University, China, and is now a postdoctoral fellow at the U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR). “This research is helping us fill a crucial gap in our understanding of coronal magnetic fields, which are the source of the energy for storms that can impact Earth.”
The international team is made of researchers from Northumbria University, UK; NSF NCAR; Peking University, China; and University of Michigan. The research was funded by a grant from the National Natural Science Foundation of China and the National Key R&D Program of China and supported by the Newkirk graduate student fellowship awarded to Yang by NSF NCAR. The UCoMP instrument was developed with support from the U.S. National Science Foundation (NSF) and is operated by NSF NCAR at the Mauna Loa Solar Observatory.
Upgraded instrument
Although scientists have been able to routinely measure the magnetic field on the Sun’s surface, known as the photosphere, it has long been difficult to measure the much dimmer coronal magnetic field. This has limited a deeper understanding of the three-dimensional structure and evolution of the magnetic field of the corona, where solar storms brew.
To measure the three-dimensional coronal magnetic fields in depth, big telescopes like NSF’s Daniel K. Inouye Solar Telescope (DKIST) are needed. With a 4-meter-diameter aperture, DKIST is the world’s largest solar telescope, and recently demonstrated its groundbreaking ability for making detailed observations of the coronal magnetic field. However, DKIST is not able to map the Sun all at once. The smaller UCoMP instrument is actually better-suited to give scientists global pictures of the coronal magnetic field, albeit at lower resolution and in a two-dimensional projection. The observations from both sources are thus highly-complementary to a holistic view of the coronal magnetic field.
UCoMP is primarily a coronagraph, an instrument that uses a disc to block out light from the Sun, similar to an eclipse, making it easier to observe the corona. It also combines a Stokes polarimeter, which images other spectral information such as coronal line intensity and Doppler velocity. Even though UCoMP has a much smaller aperture (20 cm), it is able to take a wider view which makes it possible to study the entire Sun on most days.
The researchers applied a method called coronal seismology to track magnetohydrodynamic (MHD) transverse waves in the UCoMP data. The MHD waves gave them information that made it possible to create a two-dimensional map of the strength and direction of the coronal magnetic field.
In 2020, a previous study used UCoMP’s predecessor and the coronal seismology method to produce the first map of the global coronal magnetic field. This was a crucial step toward routine coronal magnetic field measurements. UCoMP has expanded capabilities that makes it possible to make more detailed, routine measurements. During the UCoMP study, the research team produced 114 magnetic field maps between February and October 2022, or one almost every other day.
“We are entering a new era of solar physics research where we can routinely measure the coronal magnetic field,” said Yang.
Completing the picture
The observations also produced the first measurements of the coronal magnetic field in the polar regions. The Sun’s poles have never been directly observed because the curve of the Sun near the poles keeps it just beyond our view from Earth. Though the researchers didn’t directly view the poles, for the first time they were able to take measurements of the magnetism emitting from them. This was due in part to the improved data quality provided by UCoMP and because the Sun was near solar maximum. The typically weak emissions from the polar region have been much stronger, making it easier to obtain coronal magnetic field results in the polar regions.
As a postdoctoral fellow at NSF NCAR, Yang will continue his research of the Sun’s magnetic field; he hopes to improve existing coronal models that are based on measurements of the photosphere. Since the current method used with UCoMP is limited to two dimensions, it still doesn’t capture the full three-dimensional magnetic field. Yang and his colleagues hope to combine their research with other techniques to get a deeper understanding of the full vector of the magnetic field in the corona.
The third dimension of the magnetic field, oriented along a viewer's line of sight, is of particular importance for understanding how the corona is energized leading up to a solar eruption. Ultimately, a combination of a large telescope and a global field of view is needed to measure all the three-dimensional twists and tangles behind phenomena like solar eruptions; this is the motivation behind the proposed Coronal Solar Magnetism Observatory (COSMO), a 1.5-meter-diameter solar refracting telescope undergoing its final design study.
“Since coronal magnetism is the force that sends mass from the Sun flying across the solar system, we have to observe it in 3D — and everywhere all at once, throughout the global corona,” said Sarah Gibson, COSMO Development Lead and an NSF NCAR scientist co-author on the paper. "Yang's work represents a huge step forward in our ability to understand how the Sun's global coronal magnetic field changes from day to day. This is critical to our ability to better predict and prepare for solar storms, which are an ever-increasing danger to our ever-more technologically dependent lives here on Earth."
About the article: Title: Observing the evolution of the Sun’s global coronal magnetic field over eight months Authors: Zihao Yang, Hui Tian, Steven Tomczyk, Xianyu Liu, Sarah Gibson, Richard J. Morton, and Cooper Downs Journal:Science
This material is based upon work supported by the NSF National Center for Atmospheric Research, a major facility sponsored by the U.S. National Science Foundation and managed by the University Corporation for Atmospheric Research. Any opinions, findings and conclusions or recommendations expressed in this material do not necessarily reflect the views of NSF.
Observing the evolution of the Sun’s global coronal magnetic field over eight months
Article Publication Date
4-Oct-2024
In odd galaxy, NASA's Webb finds potential missing link to first stars
NASA/Goddard Space Flight Center
image:
What appears as a faint dot in this James Webb Space Telescope image may actually be a groundbreaking discovery. Detailed information on galaxy GS-NDG-9422, captured by Webb’s NIRSpec (Near-Infrared Spectrograph) instrument, indicates that the light we see in this image is coming from the galaxy’s hot gas, rather than its stars. Astronomers think that the galaxy’s stars are so extremely hot (more than 140,000 degrees Fahrenheit, or 80,000 degrees Celsius) that they are heating up the nebular gas, allowing it to shine even brighter than the stars themselves.
Credit: NASA, ESA, CSA, STScI, Alex Cameron (Oxford)
Looking deep into the early universe with NASA’s James Webb Space Telescope, astronomers have found something unprecedented: a galaxy with an odd light signature, which they attribute to its gas outshining its stars. Found approximately one billion years after the big bang, galaxy GS-NDG-9422 (9422) may be a missing-link phase of galactic evolution between the universe’s first stars and familiar, well-established galaxies.
“My first thought in looking at the galaxy’s spectrum was, ‘that’s weird,’ which is exactly what the Webb telescope was designed to reveal: totally new phenomena in the early universe that will help us understand how the cosmic story began,” said lead researcher Alex Cameron of the University of Oxford.
Cameron reached out to colleague Harley Katz, a theorist, to discuss the strange data. Working together, their team found that computer models of cosmic gas clouds heated by very hot, massive stars, to an extent that the gas shone brighter than the stars, was nearly a perfect match to Webb’s observations.
“It looks like these stars must be much hotter and more massive than what we see in the local universe, which makes sense because the early universe was a very different environment,” said Katz, of Oxford and the University of Chicago.
In the local universe, typical hot, massive stars have a temperature ranging between 70,000 to 90,000 degrees Fahrenheit (40,000 to 50,000 degrees Celsius). According to the team, galaxy 9422 has stars hotter than 140,000 degrees Fahrenheit (80,000 degrees Celsius).
The research team suspects that the galaxy is in the midst of a brief phase of intense star formation inside a cloud of dense gas that is producing a large number of massive, hot stars. The gas cloud is being hit with so many photons of light from the stars that it is shining extremely brightly.
In addition to its novelty, nebular gas outshining stars is intriguing because it is something predicted in the environments of the universe’s first generation of stars, which astronomers classify as Population III stars.
“We know that this galaxy does not have Population III stars, because the Webb data shows too much chemical complexity. However, its stars are different than what we are familiar with – the exotic stars in this galaxy could be a guide for understanding how galaxies transitioned from primordial stars to the types of galaxies we already know,” said Katz.
At this point, galaxy 9422 is one example of this phase of galaxy development, so there are still many questions to be answered. Are these conditions common in galaxies at this time period, or a rare occurrence? What more can they tell us about even earlier phases of galaxy evolution? Cameron, Katz, and their research colleagues are actively identifying more galaxies to add to this population to better understand what was happening in the universe within the first billion years after the big bang.
“It’s a very exciting time, to be able to use the Webb telescope to explore this time in the universe that was once inaccessible,” Cameron said. “We are just at the beginning of new discoveries and understanding.”
This comparison of the data collected by the James Webb Space Telescope with a computer model prediction highlights the same sloping feature that first caught the eye of astronomer Alex Cameron, lead researcher of a new study published in Monthly Notices of the Royal Astronomical Society. The bottom graphic compares what astronomers would expect to see in a "typical" galaxy, with its light coming predominantly from stars (white line), with a theoretical model of light coming from hot nebular gas, outshining stars (yellow line). The model comes from Cameron’s collaborator, theoretical astronomer Harley Katz, and together they realized the similarities between the model and Cameron's Webb observations of galaxy GS-NDG-9422 (top). The unusual downturn of the galaxy's spectrum, leading to an exaggerated spike in neutral hydrogen, is nearly a perfect match to Katz’s model of a spectrum dominated by super-heated gas. While this is still only one example, Cameron, Katz, and their fellow researchers think the conclusion that galaxy GS-NDG-9422 is dominated by nebular light, rather than starlight, is their strongest jumping-off point for future investigation. They are looking for more galaxies around the same one-billion-year mark in the universe’s history, hoping to find more examples of a new type of galaxy, a missing link in the history of galactic evolution.
Credit
NASA, ESA, CSA, Leah Hustak (STScI)
The James Webb Space Telescope is the world’s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).
Credit: Images courtesy of Christopher Reynolds and Alberto Bolatto. Composite by Mark Sherwood.
On October 3, 2024, NASA announced that two space probes proposed by University of Maryland astronomers have advanced to the next round of consideration for a $1 billion mission slated to launch into orbit in 2032.
The selected probes include the Advanced X-ray Imaging Satellite (AXIS) mission with UMD Astronomy Professor Christopher Reynolds as its principal investigator and the PRobe far-Infrared Mission for Astrophysics (PRIMA) with UMD Astronomy Professor Alberto Bolatto as a co-investigator and NASA Goddard Space Flight Center researcher and UMD Astronomy Adjunct Professor Jason Glenn as its principal investigator.
“It's a huge achievement for three of our astronomy faculty members to be leading the charge on missions that will explore the cosmos in an entirely new way,” said Amitabh Varshney, dean of the College of Computer, Mathematical, and Natural Sciences.
"This is terrific news—Chris, Alberto and Jason are true leaders in their fields,” added Andrew Harris, chair of UMD’s Department of Astronomy. “They, along with colleagues at NASA Goddard and other institutions, have made the scientific cases that drive these exciting missions forward to the next stages possible."
This announcement follows NASA’s creation of a new class of astrophysics observatories, called probes, which are smaller than “flagship” missions like the James Webb Space Telescope but still capable of tackling the big questions in astrophysics. NASA plans to select either a far-infrared or X-ray observatory to investigate the birth of planets, as well as the evolution of galaxies and black holes, in the early universe.
Over the next year, each team will receive $5 million to flesh out their plans and prototypes for AXIS and PRIMA even further. NASA will then re-review the proposals and select one mission to move forward in 2026.
Read more below about the proposed missions and what the UMD astronomers behind them hope to discover.
AXIS
AXIS will be able to peer “further and wider” into the early cosmos than previous X-ray observatories, according to Reynolds.
Thanks to new technologies that have been developed at NASA Goddard over the last few years, AXIS would be 10 times more sensitive to X-rays than the Chandra X-ray Observatory was at its launch in 1999. The biggest innovation was the development of X-ray mirrors large enough to collect numerous X-rays but sensitive enough to capture extremely high-quality images—a tricky balancing act that can yield vital planetary information.
X-rays come from extremely hot processes such as the explosion of stars or the accretion of black holes, so tracing them back to their source can paint a picture of galactic formation. As scientists search for life beyond Earth, X-rays could even offer clues about potentially habitable planets.
In extreme cases, stars with intense flares and coronal mass ejections could strip surrounding planets of their atmospheres, making those places uninhabitable. On the opposite end of the spectrum, using X-rays to find “quieter” and less active stars could help researchers find nearby planets that are potentially habitable.
“Because AXIS is so sensitive, it can detect quite easily the X-rays from other stars and categorize how active they are, how powerful their flares are and how powerful their corona is,” Reynolds said. “Then, it can start to connect that to the properties of any planets that might exist around it.”
Reynolds, who is also the director of the Joint Space-Science Institute, a research partnership between UMD and NASA Goddard, said another goal of AXIS is especially relevant to his research: observing some of the earliest black holes in the universe.
“The AXIS observatory is designed to be able to detect X-rays from the first supermassive black holes in the first 500 million years of the universe,” Reynolds said. “Some scenarios predict that we should see lots of black holes in that era, and others say that we shouldn’t. It's very much an unanswered question of when those first supermassive black holes emerged and what were their progenitors.”
Reynolds also hopes to study how central black holes, which sit in the middle of galaxies, influence the formation of stars and other celestial objects around them. While Webb has already made significant strides in black hole research, Reynolds explained that AXIS could complement or even expand on its findings.
“We have a much wider field of view than James Webb, so the patch of sky we're looking at is much larger. That means that we can survey the sky in a more efficient and faster way,” Reynolds said. “We are looking forward to the next generation of X-ray astronomy.”
PRIMA
PRIMA has similar goals to AXIS—including exploring the formation of black holes and stars—but it would see the early universe a lot differently. PRIMA is designed to pick up on far-infrared radiation, which, according to Bolatto, is an “underserved” wavelength in astronomy missions.
The Herschel Space Observatory, which was operational from 2009 to 2013, was the last space observatory capable of detecting these longer wavelengths. Bolatto said that one advantage of a far-infrared observatory is its ability to “cut through the muck” of cosmic dust and gas in a way that past and present telescopes, including Webb, could not do as efficiently. This would allow PRIMA to simultaneously study the growth of black holes and their host galaxies when they are heavily obscured, which is a common experience in the early universe.
While astronomers ultimately want to peer past space dust to see other objects, PRIMA researchers will also pause to analyze the odd amalgamation of rock, minerals and other materials in their path.
“We don't know how dust happens,” Bolatto said. “We sometimes measure very large quantities of dust in the very early history of the universe, but it’s not clear where it comes from. So understanding how that process happens is part of what we’re trying to achieve.”
With PRIMA, researchers also want to look back to a time before the planets formed. They plan to analyze protoplanetary disks—collections of gas and dust orbiting young stars that are the birthplace of planets—to determine how much water is needed for different types of planets to form. Doing so could even uncover where Earth’s water came from, a mystery that has not been definitively solved.
“We can see protoplanetary disks now, but measuring how massive they are is incredibly difficult with radio astronomy or with near-infrared probes,” Bolatto said. “With PRIMA, we will be able to measure the mass of protoplanetary disks directly in a much better way than anybody has been able to do up till now.”
Bolatto noted that PRIMA’s cutting-edge technologies should enable plenty of new discoveries. Like Webb, PRIMA’s telescope would be cryogenically cooled to reduce infrared background noise, but it will reach even colder temperatures—about 4.5 K, or -450 degrees Fahrenheit—to improve the instrument’s sensitivity.
PRIMA would also be outfitted with a wide-field camera, a high-resolution spectrograph to study the chemical composition of cosmic objects not seen before and state-of-the-art kinetic inductance detectors developed by NASA’s Jet Propulsion Laboratory in collaboration with Goddard to measure far-infrared radiation. Goddard would also equip PRIMA with a high-resolution spectrometer, enabling scientists to detect water in protoplanetary disks as well as galactic winds caused by supermassive black holes.
Glenn said that he and his colleagues are excited to see what comes next for PRIMA.
“The PRIMA team is excited and grateful for this opportunity to develop a concept for the first NASA Astrophysics Probe Explorer,” Glenn said. “Our extraordinary team of scientists and engineers is going to enable humankind to understand how black holes and galaxies evolved together and how planets got their atmospheres."
Bolatto added that PRIMA could be a gamechanger for astrophysics if it’s ultimately selected to become the next probe mission.
“The excitement is that we are going to get to see a completely new sky because there are things that we couldn't dream of doing 10 years ago that we will be able to do with the technology we have now,” Bolatto said. “The amount of science that can come out of PRIMA would be fantastic.”
Renderings of AXIS (left) and PRIMA
Credit
Images courtesy of Christopher Reynolds and Alberto Bolatto. Composite by Mark Sherwood.
Glimmers of antimatter to explain the "dark" part of the universe
Traces of antimatter in cosmic rays reopen the search for 'WIMPs' as dark matter
Sissa Medialab
image:
The image shows the predicted flux of antihelium-3 produced from dark matter (WIMPs) that annihilate producing these antinuclei. Each color represents the prediction for a different mass of dark matter, as shown in the legend. t The bands are almost touching the AMS-02 sensitivity, which means that in some optimistic cases, WIMPs can explain this discrepancy.
One of the great challenges of modern cosmology is to reveal the nature of dark matter. We know it exists (it constitutes over 85% of the matter in the Universe), but we have never seen it directly and still do not know what it is. A new study published in JCAP has examined traces of antimatter in the cosmos that could reveal a new class of never-before-observed particles, called WIMP (Weakly Interacting Massive Particles), which could make up dark matter. The study suggests that some recent observations of "antinuclei" in cosmic rays are consistent with the existence of WIMPs, but also that these particles may be even stranger than previously thought.
"WIMPs are particles that have been theorized but never observed, and they could be the ideal candidate for dark matter," explains Pedro De la Torre Luque, a physicist at the Institute of theoretical physics in Madrid other and other particles only through gravity and the weak interaction force, one of the four fundamental forces that operates only at very close distances."
A few years ago, the scientific community hailed a "miracle": WIMPs seemed to meet all the requirements for dark matter, and it was thought—once it was "imagined" what they could be and how they could be detected—that within a few years we would have the first direct evidence of their existence. On the contrary, research in recent years has led to the exclusion of entire classes of these particles, based on their peculiar emissions. Today, although their existence has not been entirely ruled out, the range of possible WIMP types has narrowed significantly, along with the methodologies for trying to detect them. "Of the numerous best-motivated proposed models, most have been ruled out today and only a few of them survive today," says De la Torre Luque.
A recent discovery, however, seems to have reopened the case. "These are some observations from the AMS-02 experiment," De la Torre Luque explains. AMS-02 (Alpha Magnetic Spectrometer) is a scientific experiment aboard the International Space Station that studies cosmic rays. "The project leaders revealed that they detected traces of antinuclei in cosmic rays, specifically antihelium, which no one expected."
To understand why these antinuclei are important for WIMPs and dark matter, one must first understand what antimatter is.
Antimatter is a form of matter with electrical charge opposite to that of "normal" matter particles. If you've followed physics lessons in school, you'll know that ordinary matter, the stuff around us, is made up of particles with negative electric charge, like electrons, positive charge (protons), or neutral charge. Antimatter is composed of "mirror" particles with opposite charges (a "positive" electron, the positron, a "negative" proton, etc.). When matter and antimatter meet, they annihilate each other, emitting strong gamma radiation. In our universe, composed overwhelmingly of normal matter, there is a small amount of antimatter, sometimes closer than one might think, given that positrons are used as contrast agents for PET, the medical imaging exam that some of you may have undergone.
Some of this antimatter was formed—scientists believe—during the Big Bang, but more is constantly created by specific events, which makes it very significant to observe. "If you see the production of antiparticles in the interstellar medium, where you expect very little, it means something unusual is happening," De la Torre Luque explains. "That's why the observation of antihelium was so exciting."
What produces the antihelium nuclei observed by AMS-02 could indeed be WIMPs. According to the theory, when two WIMP particles meet, in some cases they annihilate, meaning they destroy each other, emitting energy and producing both matter and antimatter particles. De la Torre Luque and his colleagues have tested some of the WIMP models to see if they are compatible with the observations.
The study confirmed that some observations of antihelium are hard to explain with known astrophysical phenomena. "Theoretical predictions suggested that, even though cosmic rays can produce antiparticles through interactions with gas in the interstellar medium, the amount of antinuclei, especially antihelium, should be extremely low," De la Torre Luque explains. "We expected to detect one antihelium event every few tens of years, but the around ten antihelium events observed by AMS-02 are many orders of magnitude higher than the predictions based on standard cosmic-ray interactions. That's why these antinuclei are a plausible clue to WIMP annihilation."
But there may be more. The antihelium nuclei observed by AMS-02 are of two distinct isotopes (the same element, but with a varying number of neutrons in the nucleus), antihelium-3 and antihelium-4. Antihelium-4, in particular, is much heavier and also much rarer.
We know that the production of heavier nuclei becomes increasingly unlikely as their mass increases, especially through natural processes involving cosmic rays, which is why seeing so many of them is a warning sign. "Even in the most optimistic models, WIMPs could only explain the amount of antihelium-3 detected, but not antihelium-4," De la Torre Luque continues, and this would require imagining a particle (or class of particles) even stranger than the WIMPs proposed so far, or in technical jargon, even more "exotic."
Thus, De la Torre Luque and his colleagues' study indicates that the path toward WIMPs is not yet closed. Many more precise observations are now needed, and we may have to expand or adapt the theoretical model, perhaps introducing a new dark sector into the standard model of known particles to date, with new "exotic" elements.
Flux of antideuterons
Predicted flux of antideuterons produced from dark matter (WIMPs) that annihilate producing these antinuclei. Each color represents the prediction for a different mass of dark matter, as shown in the legend. We see that WIMPs can produce the antideuteron flux observed by AMS-02 as well.
Expected antideuteron flux produced from the interactions of cosmic rays
Expected antideuteron flux produced from the interactions of cosmic rays (high-energy particles in the Galaxy, mainly protons and helium) with the gas in the interstellar medium. These are compared with the flux of antideuteron that different experiments can detect (GAPs, the experiment that will be launched by the end of this year, and AMS-02, that has two detectors, the RICH and the TOF). In this figure you can see that the flux produced (the blue band) from cosmic-ray interactions may explain some events observed by the AMS experiment.
Expected antihelium-3 flux produced from the interactions of cosmic rays (high-energy particles in the Galaxy, mainly protons and helium) with the gas in the interstellar medium.CreditDe la Torre Luque
Journal
Journal of Cosmology and Astroparticle Physics
Method of Research
Data/statistical analysis
Article Title
Cosmic-Ray Propagation Models Elucidate the Prospects for Antinuclei Detection
Article Publication Date
4-Oct-2024
Astrophysicist Ylva Götberg named TIME100 Emerging Leader
ISTA Assistant Professor Götberg in TIME100 NEXT list of 100 emerging leaders
Institute of Science and Technology Austria
image:
ISTA Assistant Professor Ylva Götberg. The astrophysicist was named to TIME100 Next—TIME’s list of the next 100 most influential people in the world.
A rising star from the Institute of Science and Technology Austria (ISTA) made the 2024 TIME100 Next list. TIME100 Next highlights emerging leaders from around the world who are shaping the future and defining the next generation of leadership in their fields.
One of the first astrophysicists to join ISTA a year ago, Assistant Professor Ylva Götberg helped set the cornerstone of this discipline at the young and rapidly growing Institute. Götberg specializes in studying the evolution of massive binary stars. Binary stars are pairs of stars locked together in an eternal waltz with dramatic consequences. These stars can come so close to one another that interaction becomes inevitable: One can strip its companion of its outer layers or even engulf it.
As a young group leader, Götberg focuses on teamwork, collaboration, diversity, and mutual respect. “In my group, I want to promote a culture of collaboration with my team members, moving away from rigid supervision. Young researchers come to science through different paths, from different backgrounds, and with different goals. I want to be able to provide my team members with an experience that benefits them.”
Pushing scientific boundaries with theory-driven research
Götberg is a young group leader who obtained her PhD from the University of Amsterdam in the Netherlands in 2019. She joined ISTA in September 2023, following her experience as a NASA Hubble Postdoctoral Fellow at the Carnegie Observatories in Pasadena, California. Götberg is driven by questions like where to take science next, which theory will open up unforeseen possibilities, or even what could make scientists’ little castle of theories fail. “We must be able to rebuild our castle of scientific theories and strengthen its walls so it can sustain the incoming impacts from new findings, such as new telescope surveys and space missions.”
Although scientific discoveries are largely viewed as impactful and exciting, Götberg, a theoretician at heart, highlights the importance of reinforcing scientific foundations with a solid structure of testable theories. “A theory may feel less exciting than a discovery, but rigorous theoretical work is necessary to develop science. I find it especially exciting when I manage to create a theory so refined and elaborate that I can test it to prove or disprove it. I also find it very humbling—and exciting—when a testable theory I created turns out to be wrong. Exciting, because by knowing that a theory failed, we can take a step forward, reorient, and start navigating in the right direction,” Götberg says.
A leadership style that focuses on interpersonal relations
On top of her stellar scientific achievements, Götberg is developing various leadership skills. She has been a member of multiple review panels, evaluating student fellowships and support systems, and served on telescope allocation committees. At ISTA, Götberg is growing her research group by setting the focus on interpersonal relationships within the team: “I want to be an approachable mentor. As a team leader, I want to be flexible, available, and versatile to find effective ways to cooperate with my group members. I am conscious of the challenges and want to reach each team member and help them reach each other.”
Inspiring future scientists to explore their passions and interests
Researching stars might in and of itself be an inspiring endeavor. However, Götberg is also conscious of the biases in her research field: “I hope to inspire young people, especially women who don’t dare to go into STEM, just because it’s outside the norm. Such biases are a loss for science, as we end up losing potentially brilliant future scientists who choose a different career path.”
Götberg is convinced that physics and astronomy need to diversify by opening up to new researchers from various backgrounds and cultures. Working in different environments helped her understand that the more diverse the team, the more included, and the happier the team members feel, which leads naturally to scientific progress. “Diversity favors inclusion and mutual respect and allows each team member to understand their own difference from the others. Accepting every person’s difference, starting from oneself, makes people more welcoming,” she says.
Nomination to TIME100 Next, a sense of responsibility
Götberg feels honored and grateful to be named to the TIME100 Next list. She sees this as a form of recognition for young, female scientists. She is also aware that being on this list of 100 emerging leaders comes with the responsibility of representation and inspiration. “I’d like to highlight that the people you work with matter most. The team around you is what will make you succeed. Science is really about people, and working in close collaborations allows me to be more productive and have a positive mindset,” she says. “I was delighted to know that TIME100 Next picked me together with my collaborator Maria Drout, with whom I have co-first authored the Science paper on the missing star population. Maria and I work very well together and are lucky to be supported by an excellent team of researchers. I’m very pleased that we made it to this list together.”
Visualization of a binary star experiencing mass transfer.
UVEX capabilities compared to select other UV telescopes. Illustration with simulated images demonstrating UVEX’s special resolving power and spectrographs.
Two NASA employees awarded Space and Satellite Professionals 20 under 35 of 2024
NASA/Goddard Space Flight Center
image:
Two NASA employees, Howard Chang (r) and Bradley Williams (L), were named as two of the “20 under 35 of 2024” by the Space and Satellite Professionals International. The award recognizes outstanding young professionals in the space industry.
Credit: Photos courtesy of Bradley Williams and Howard Chang
Two NASA employees, Howard Chang and Bradley Williams, were named as two of the “20 under 35 of 2024” by the Space and Satellite Professionals International. The award recognizes outstanding young professionals in the space industry.
The annual list of “20 Under 35” features 20 employees and entrepreneurs to keep your eye on in coming years. They were selected from nominations submitted by the membership and evaluated by the same panel of judges who name winners of the Promise Awards.
Howard Chang is an Assistant Chief Counsel at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Bradley (Brad) Williams is the Acting Associate Director for Flight, Heliophysics Division, NASA Science Mission Directorate at NASA Headquarters, Washington.
“I’m honored to be named in this year’s cohort,” Chang said. “I saw how SSPI connects people across the space and satellite industry—across generations, countries, and even disciplines—to build up the space economy of the future. And I can’t express enough thanks to all my NASA colleagues for their support and kindness—especially Deputy Chief Counsel Amber Hufft for her time and mentorship this year.”
“It is an absolute honor to be recognized by SSPI on the 20 under 35 list of 2024,” said Williams. “I feel privileged to have benefitted from the opportunities I’ve had so far in my career. I want to thank the numerous mentors through the years who have provided me guidance and lessons learned and especially my colleagues and the leaders at NASA who have recognized my contributions and supported my growth potential as a leader.”
About Howard Chang
Howard Chang serves as the lead attorney for NASA’s Wallops Flight Facility’s commercial, nonprofit, and interagency partnerships in Wallops Island, Virginia. He also focuses on legal issues involving Unmanned Aircraft Systems (UAS), small UAS, real property transactions, government contracts litigation and administration supporting NASA Goddard, and partnerships involving the Goddard Institute for Space Studies located at Columbia University, New York, NASA commended Chang with an individual merit award in recognition of his superior support to the Goddard Space Flight Center during his first six months.
In addition to his legal work, Chang contributes substantially to thought leadership in space law and policy. He has authored articles for The Federalist and the International Institute of Space Law on topics from the Apollo 8 mission to the travaux preparatoires of the Principles Declaration of 1963—the precursor to the Outer Space Treaty. He is a frequent speaker on matters of space law. He will be presenting at the 2024 International Astronautical Congress in Milan, Italy on the Wolf Amendment and the future of the International Space Station. In Milan, he will present in his capacity as an Advisor for the Georgetown University Space Initiative. He continues to serve as a guest lecturer on space policy for law schools and undergraduate space courses as well.
Chang previously worked at an international firm in its aerospace finance and space law practices, engaging in litigation, transactional, regulatory, and policy work for aerospace and space companies. In addition, he worked on white-collar criminal defense, internal corporate investigations, congressional investigations, trial litigation, appellate litigation, and national security matters.
About Bradley Williams
Bradley Williams is the acting Associate Director for Flight Programs in the Heliophysics Division of the Science Mission Directorate at NASA Headquarters, Washington where he oversees more than a dozen missions in operations and approximately another dozen missions in different stages of development.
Previously, Williams was a Program Executive in the Heliophysics Division where his assignments included IMAP, TRACERS, HelioSwarm, the Solar Cruiser solar sail technology project, and Senior Program Executive of the NASA Space Weather Program.
Before joining NASA, he was the Director of Civil Space Programs at Terran Orbital Corporation, where he led the spacecraft development for both commercial and NASA technology demonstration missions and assisted with the growth of the science mission portfolio.
Previously at the University of Arizona, he worked with faculty and research teams to identify proposal opportunities and develop spaceflight proposals. Williams was a vital member of the OSIRIS-REx Camera Suite (OCAMS) team. He also served as the Deputy Payload Manager on GUSTO, the first of its kind, balloon-borne observatory.
He has been recognized for his achievements being named a Via Satellite Rising Star in 2024 and has been awarded the Robert H. Goddard Engineering Team Award, NASA Group Achievement Award, and asteroid (129969) Bradwilliams named in his honor.
The “20 Under 35“ are honored each year at SSPI’s Future Leaders Dinner. At the Dinner, SSPI presents the three top-ranked members of the 20 Under 35 with a Promise Award, recognizing them as leaders of their year’s cohort, and honors the Mentor of the Year for fostering young talent, both within his or her organization and throughout the industry. The 2024 “20 Under 35” will be honored at the Future Leaders Celebration on October 21, 2024 during Silicon Valley Space Week.
GPS jamming? No problem, LEO satellites hold the key to resilient, interference-free navigation
A new study from the University of Vaasa explores advanced positioning technologies to enhance navigation accuracy and reliability
Credit: Photo by Riikka Kalmi / University of Vaasa
Increasingly occurring GPS jamming in Finland disrupts the daily civilian activities, posing major navigational challenges. A new patented method using Low Earth Orbit (LEO) satellites and massive Multiple Input Multiple Output (MIMO) antennas addresses these location vulnerability issues, presenting means for precise navigation even where traditional global navigation satellite systems (GNSS) fail. This breakthrough was verified in a recent doctoral dissertation by Mahmoud Elsanhoury, from the University of Vaasa.
Mahmoud Elsanhoury's doctoral dissertation at the University of Vaasa explores advanced positioning technologies to enhance navigation accuracy and reliability. The research covers multiple areas, including the development of a precise Ultra-Wideband (UWB) system for dense indoor environments, which is also known as “the indoor GPS”, improvements in outdoor vehicular positioning using GNSS, and a novel LEO satellite-based positioning method that addresses many of the limitations of current GNSS systems. Elsanhoury’s work involved extensive testing and simulations, demonstrating significant advancements in both indoor and outdoor positioning accuracy.
– While advanced positioning technologies are crucial for overcoming challenges in navigation, including overcoming GPS jamming and interference, many current systems still fail in providing reliable solutions, says Mahmoud Elsanhoury, who will be defending his dissertation on October 3, 2024 at the University of Vaasa.
Elsanhoury's doctoral research focuses on two distinct technologies: UWB systems for precise indoor positioning and LEO satellites for enhanced outdoor navigation. The UWB technology significantly enhances positioning accuracy within dense indoor settings, while the LEO satellite-based system addresses the limitations of traditional GNSS.
Leo satellites: a novel solution for outdoor navigation
For outdoor environments, Elsanhoury’s research introduces a novel LEO satellite-based positioning method. This approach addresses the impact of GPS jamming and interference, which is a persistent challenge in Finland and other regions. The LEO satellite system employs multiple signal beams to enhance navigation reliability, ensuring accurate positioning even when traditional GNSS systems are compromised.
The simulation results conducted were very promising as the new LEO-based method outperformed GNSS amid challenging road conditions, with improved LEO accuracy of 9.15 meters compared to GNSS accuracy of 26.6 meters.
– In outdoor environments, our methods showed more than 60%–190% improvements in positioning accuracy.
The new, patented method has received international endorsement and recognition.
– I have presented our LEO-MIMO invention at several international venues including in Japan, Germany, Belgium, and Spain. Every discussion with industry professionals has reaffirmed the substantial potential of our invention, particularly in delivering reliable location information with optimised resource usage and reduced risks. Recently, this patented idea won the EUNICE Entrepreneurial Award 2024 in Spain, says Elsanhoury.
Mahmoud Elsanhoury also believes the positioning technologies discussed in his doctoral dissertation could be applied to extra-terrestrial environments such as the Moon and Mars, especially as space agencies such as NASA and ESA are actively pursuing sustainable human presence in space.
Ultra wideband: a key technology for indoor navigation
The development of advanced UWB systems is crucial for navigating complex indoor spaces. The technology has shown resilience in dense industrial environments, also overcome the common wireless communication impairments. Integrating UWB with other assisting technologies such as inertial motion sensors can lead to more precise location information, and solving challenges posed by traditional systems in confined areas.
Elsanhoury’s experiments carried out in the Technobothnia laboratory on Vaasa Campus have shown substantial improvements in indoor positioning compared to typical standard methods with mean absolute accuracy of 4.7 centimeters only. The results are very promising for various applications such as smart logistics and automated systems.
Mahmoud Elsanhoury’s research activities have earned him several recognitions, including the NOKIA Foundation scholarship, Innovation of the Year award at the University of Vaasa, selection as one of the Top-10 young scientists in Finland, representing Finland at the global young scientists summit (GYSS) in Singapore, and winning the EUNICE entrepreneurial competition in Spain.
Doctoral dissertation
Elsanhoury, Mahmoud (2024) Towards Precision Positioning for Smart Logistics Using Ultra Wide-Band Systems and LEO Satellite-Based Technologies. Acta Wasaensia 534. Doctoral dissertation. Vaasan yliopisto. University of Vaasa.
The public examination of MSc. Mahmoud Elsanhoury’s doctoral dissertation, "Towards Precision Positioning For Smart Logistics Using Ultra Wide-Band Systems and LEO Satellite-Based Technologies," will take place on Thursday, October 3, 2024, at 12 noon in the Nissi Auditorium at the University of Vaasa.
It is also possible to participate in the defence online via Zoom (password: 440699)
Professor Jari Nurmi (Tampere University) and Professor Simo Särkkä (Aalto University) will act as opponents, while Professor Mohammed Elmusrati (University of Vaasa) will act as a custos for the examination. Professor Heidi Kuusniemi and Dr. Janne Koljonen are co-supervisors.
No comments:
Post a Comment