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Webb Sees Asteroids Collide in Another Star System
The James Webb Space Telescope (JWST) continues to make amazing discoveries. This time in the constellation of Pictor where, in the Beta Pictoris system a massive collision of asteroids. The system is young and only just beginning its evolutionary journey with planets only now starting to form. Just recently, observations from JWST have shown significant energy changes emitted by dust grains in the system compared to observations made 20 years ago. Dust production was thought to be ongoing but the results showed the data captured 20 years ago may have been a one-off event that has since faded suggesting perhaps, an asteroid strike!
Beta Pictoris is a young star located 63 light years away in the constellation Pictor. It has become well known for its fabulous circumstellar disk of gas and dust out of which a new system of planets is forming. It has been the subject of many a study because not only does it provide an ideal opportunity to study planetary formation but one of those planets Beta Pictoris b has already been detected.
Beta Pictoris is located about 60 light-years away towards the constellation of Pictor (the Painter’s Easel) and is one of the best-known examples of a star surrounded by a dusty debris disc. Earlier observations showed a warp of the disc, a secondary inclined disc and comets falling onto the star, all indirect, but tell-tale signs that strongly suggested the presence of a massive planet. Observations done with the NACO instrument on ESO’s Very Large Telescope in 2003, 2008 and 2009, have proven the presence of a planet around Beta Pictoris. It is located at a distance between 8 and 15 times the Earth-Sun separation — or Astronomical Units — which is about the distance Saturn is from the Sun. The planet has a mass of about nine Jupiter masses and the right mass and location to explain the observed warp in the inner parts of the disc. This image, based on data from the Digitized Sky Survey 2, shows a region of approximately 1.7 x 2.3 degrees around Beta Pictoris. Credit: ESO/Sky Survey IIWind the clock back 20 years and the Spitzer infra-red observatory was observing Beta Pictoris. It was looking for heat being emitted by crystalline silicate minerals which are often found around young stars and on celestial bodies. Back in 2004-2005 no traces were seen suggesting a collision occurred among asteroids destroying them and turning their bodies into find dust particles, smaller even than grains of sand and even powdered sugar.
Radiation was detected at the 17 and 24 micron wavelengths by Spitzer, the result of significant amounts of dust. Using JWST, the team studied radiation from dust particles around Beta Pictoris and were able to compare with these Spitzer findings. They were able to identify the composition and size of particles in the same area around Beta Pictoris that was studied by Spitzer. They found a significant reduction in radiation at the same wavelengths from 20 years ago.
The Spitzer Space Telescope observatory trails behind Earth as it orbits the Sun. Credit: NASA/JPL-CaltechAccording to Christine Chen, lead astronomer from the John Hopkins University ‘With Webb’s new data, the explanation we have is that, in fact, we witnessed the aftermath of an infrequent, cataclysmic event between large asteroid-sized bodies, marking a complete change in our understanding of this star system.’
By tracking the distribution of particles across the circumstellar disk, the team found that the dust seems to have been dispersed outward by radiation from the hot young star. Previously with observations from Spitzer, dust surrounded the star which was heated up by its thermal radiation making it a strong thermal emitter. This is no longer the case as that dust has moved, cooled and no longer emits those thermal features.
The discovery has adjusted our view of planetary system formation. Previous theories suggested that small bodies would accumulate and replenish the dust steadily over time. Instead, JWST has shown that the dust is not always replenished with time but that it takes a cataclysmic asteroid impact to seed new planetary systems with new dust. The team estimate the asteroid that was pulverised was about 100,000 times the size of the asteroid that killed the dinosaurs!
Source : WEBB TELESCOPE REVEALS ASTEROID COLLISION IN NEIGHBORING STAR SYSTEM
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Bright Rocks and “Bright Angel”
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Bright Rocks and “Bright Angel” NASA’s Mars Perseverance rover acquired this image using its Right Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rover’s mast.
This image was acquired on May 29, 2024 (Sol 1164) at the local mean solar time of 12:40:40.
NASA/JPL-Caltech/ASULast week the Perseverance rover descended into Neretva Vallis, an ancient river channel that brought water into Jezero Crater billions of years ago. Rocks found in Neretva Vallis could have come from far upstream, giving us the opportunity to examine material which may have come from many kilometers away. Turning north into the channel has allowed us to complete longer drives, a refreshing change of pace from the rugged terrain we tackled in the Western Margin.
Dodging dunes at Dunraven Pass, we approached Mount Washburn, an outcrop which our Mastcam-Z camera identified from a distance as having spectrally diverse boulders and patches of lighter-toned bedrock. Upon arriving, we were amazed by the variety of colors and textures in the rocks around the rover and immediately got to work planning observations with our remote sensing instruments. Much of our focus was on “Atoko Point”, a bright boulder with dark speckles. After acquiring numerous Mastcam-Z multispectral images and zapping Atoko Point with our SuperCam laser, we began to look towards our next goal: “Bright Angel”. This exposure of light-toned rock, northwest of our current location, stands out vividly in orbital imagery. By examining outcrops at Bright Angel and assessing stratigraphic relationships (i.e. the vertical sequence and stacking of different sets of rocks), it is hoped that we can understand its connection to Neretva Vallis and the crater rim.
Intrigued by what we have found at Mount Washburn, our first stop in the channel, we have now turned to the terrain to the north, where we will add yet another chapter to Perseverance’s story at “Bright Angel”.
Written by Henry Manelski, PhD Student at Purdue University
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If Gravity Can Exist Without Mass, That Could Explain Dark Matter
Dark Matter is Nature’s poltergeist. We can see its effects, but we can’t see it, and we don’t know what it is. It’s as if Nature is playing tricks on us, hiding most of its mass and confounding our efforts to determine what it is.
It’s all part of the Universe’s “missing mass” problem. Actually, it’s our problem. The Universe is what it is. It’s our understanding of the Universe, mass, and gravity that’s the problem. And a solution is proving to be elusive.
Whatever the missing mass is or whatever causes the effects we observe, we have a placeholder name for it: dark matter. And it makes up 85% of the matter in the Universe.
Could dark matter be primordial black holes? Could it be axions? How about WIMPS? Are dark photons its force carrier? There’s lots of theoretical thought but no conclusion.
New research in the Monthly Notices of the Royal Astronomical Society says that our hunt for dark matter may be off-track. Instead of looking for a type of particle, the solution might lie in a type of topological defect found throughout the Universe that has its roots in the Universe’s early stages.
The new research is in a paper titled “The binding of cosmological structures by massless topological defects.” The author is Richard Lieu, a distinguished professor of physics and astronomy at the University of Alabama at Huntsville.
“There is then no need to perpetuate this seemingly endless search for dark matter.”
Dr. Richard Lieu, Professor, University of Alabama, HuntsvilleAs the paper’s title makes clear, dark matter has a binding effect on structures like galaxies. Astronomers know that galaxies don’t have enough measurable mass to hold themselves together. By measuring the mass of the stars and gas in galaxies, it became clear that the visible components of the galaxies don’t provide enough mass to hold themselves together. They should simply dissipate into their constituent stars and clouds of gas.
But galaxies don’t dissipate, and scientists have concluded that something is missing. Professor Lieu has another idea.
“My own inspiration came from my pursuit for another solution to the gravitational field equations of general relativity — the simplified version of which, applicable to the conditions of galaxies and clusters of galaxies, is known as the Poisson equation — which gives a finite gravitation force in the absence of any detectable mass,” said Lieu. “This initiative is in turn driven by my frustration with the status quo, namely the notion of dark matter’s existence despite the lack of any direct evidence for a whole century.”
An entire century is a long time in the age of modern science. It’s not surprising that Nature has the power to confound us, but it is somewhat surprising that very little progress has been made on the problem. Scientists have made great progress in understanding how dark matter influences the Universe’s large-scale structure, an impressive feat, but haven’t figured out what it is.
“The nature of dark matter (DM), defined specifically in this letter as an unknown component of the cosmic substratum responsible for the extra gravitational field that binds galaxies and clusters of galaxies, has been an enigma for more than a century,” Dr. Lieu writes in his paper.
Lieu’s work leans on phase transitions in the Universe. These are episodes when the state of matter in the Universe changes. Not locally but across the entire cosmos. One example is when the Universe cooled enough to allow the strong force to bind quarks into protons and neutrons.
Dr. Lieu contends that topological defects could have formed during one of these phase transitions. These defects can take the shape of shell-like compact regions where matter density is much higher. When arranged in concentric rings, these defects behave like gravity but don’t have mass.
“It is unclear presently what precise form of phase transition in the universe could give rise to topological defects of this sort,” Lieu says. “Topological effects are very compact regions of space with a very high density of matter, usually in the form of linear structures known as cosmic strings, although 2-D structures such as spherical shells are also possible. The shells in my paper consist of a thin inner layer of positive mass and a thin outer layer of negative mass; the total mass of both layers — which is all one could measure, mass-wise — is exactly zero, but when a star lies on this shell it experiences a large gravitational force pulling it towards the center of the shell.”
So, despite our inability to measure the mass, it’s there, and other objects respond to it. Mass warps space-time and affects even massless photons. That fact underlies our ability to use gravitational lensing. We use the mass of galaxy clusters in gravitational lensing. A set of spherical shells, as Lieu talks about, could cause the same effect.
This illustration shows the gravitational lensing phenomenon. Astronomers use it to study very distant and very faint objects. Note that the scale has been greatly exaggerated in this diagram. In reality, the distant galaxy is much further away and much smaller. Image Credit: NASA, ESA & L. Calcada“Gravitational bending of light by a set of concentric singular shells comprising a galaxy or cluster is due to a ray of light being deflected slightly inwards — that is, towards the center of the large-scale structure, or the set of shells — as it passes through one shell,” Lieu notes. “The sum total effect of passage through many shells is a finite and measurable total deflection which mimics the presence of a large amount of dark matter in much the same way as the velocity of stellar orbits.”
Since astronomers measure galaxy and galaxy cluster masses by measuring the light they deflect and the way they affect the orbit of stars, astronomers could be measuring topological defects rather than particles that comprise dark matter.
“Both the deflection of light and stellar orbital velocities is the only means by which one gauges the strength of the gravitational field in a large-scale structure, be it a galaxy or a cluster of galaxies,” Dr. Lieu says. “The contention of my paper is that at least the shells it posits are massless. There is then no need to perpetuate this seemingly endless search for dark matter.”
In 2022, researchers discovered a giant arc in the sky. It spans 1 Gigaparsec and is nearly symmetrical. It’s one of several large-scale structures that seems to go against the Standard Model and the Cosmological Principle it’s based on.
These are three separate data images of the Giant Arc discovered in 2022. The paper provides details. Image Credit: Lopez et al. 2022, 10.1093/mnras/stac2204“The observation of giant arcs and rings could lend further support to the proposed alternative to the DM model,” Lieu writes in his paper. He also points out that the shells he proposes needn’t be a complete sphere.
If these shells exist, their alignment would also govern the formation and shape of galaxies and clusters. Future research will determine exactly how these shells form. “This paper does not attempt to tackle the problem of structure formation,” Lieu says. In fact, Lieu acknowledges that there’s currently no way to even observe how they might form.
“A contentious point is whether the shells were initially planes or even straight strings, but angular momentum winds them up. There is also the question of how to confirm or refute the proposed shells by dedicated observations,” Lieu says.
An experienced scientist, Lieu knows the limits of what he’s proposing.
“Of course, the availability of a second solution, even if it is highly suggestive, is not by itself sufficient to discredit the dark matter hypothesis — it could be an interesting mathematical exercise at best,” Lieu concludes. “But it is the first proof that gravity can exist without mass.”
The post If Gravity Can Exist Without Mass, That Could Explain Dark Matter appeared first on Universe Today.
NASA Sets Coverage for U.S. Spacewalk 90 Outside Space Station
NASA will provide live coverage, beginning at 6:30 a.m. EDT Thursday, June 13, as two astronauts conduct a spacewalk outside of the International Space Station. The spacewalk is scheduled to begin at 8 a.m. and last about six and a half hours.
NASA will stream the spacewalk on NASA+, NASA Television, the NASA app, YouTube, and the agency’s website. Learn how to stream NASA TV through a variety of platforms including social media.
NASA astronauts Tracy C. Dyson and Matt Dominick will exit the station’s Quest airlock to complete the removal of a faulty electronics box, called a radio frequency group, from a communications antenna on the starboard truss of the space station. The pair also will collect samples for analysis to understand the ability of microorganisms to survive and reproduce on the exterior of the orbiting laboratory.
Dyson will serve as spacewalk crew member 1 and will wear a suit with red stripes. Dominick will serve as spacewalk crew member 2 and will wear an unmarked suit. U.S. spacewalk 90 will be the fourth for Dyson and the first for Dominick in support of the space station.
Following the completion of the spacewalk, NASA will announce participating crew members for U.S. spacewalks 91 and 92, scheduled for Monday, June 24 and Tuesday, July 2, and will provide additional coverage details.
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NASA Awards Contract for Safety and Mission Assurance Services
NASA has selected KBR Wyle Services LLC, of Fulton, Maryland, to provide safety and mission assurance services to the agency.
The Safety and Mission Assurance, Audits, Assessments, and Analysis (SA3) Services contract is a cost-plus-fixed-fee contract with an indefinite-delivery/indefinite-quantity provision and a maximum potential value of approximately $75.3 million. The three-year base performance period of this contract begins August 1, 2024, and is followed by a two-year option, which would end July 31, 2029.
The SA3 contract will provide safety and mission assurance services to NASA Headquarters in Washington and other NASA centers, programs, projects, and activities through the NASA Safety Center in Cleveland. These services include, but aren’t limited to, audit/assessment/analysis support, safety assessments and hazard analysis, reliability and maintainability analysis, risk analysis and management, supply chain data management and analytics, software safety and assurance, training and outreach, quality engineering and assurance, and information systems support.
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Glenn Research Center, Cleveland
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North Carolina Volunteers Work Toward Cleaner Well Water
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North Carolina Volunteers Work Toward Cleaner Well Water Road closure due to flooding. Volunteers helped NASA scientists predict where floods like these will contaminate well water. Image credit: Kelsey Pieper
When the ground floods during a storm, floodwaters wash bacteria and other contaminants into private wells. But thanks to citizen scientists in North Carolina, we now know a bit more about how to deal with this problem. A new NASA-Funded study describes the contributions of these volunteers and how their work makes other disaster data more useful.
After Hurricane Florence, the North Carolina Department of Health and Human Services distributed sampling bottles to 754 private well users upon request. They asked these volunteers to collect samples at their wellheads or outdoor taps. As expected, the rates of fecal contamination measured with help from the volunteers were almost 8 times higher than during routine conditions.
The new study compares the water quality measurements made by volunteers to predictions from various kinds of flood boundary maps made using data from NASA’s Landsat, Sentinel, and MODIS satellites. Turns out, the flood boundary maps are pretty good predictors—under certain conditions. Now we know how to better use them for this purpose in the future, thanks to help from citizen scientists!
Contact your local health department and tell them you are interested in testing your own well water supply!
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A New Way to Search for the First Stars in the Universe
Observing the earliest stars is one of the holy Grails of astronomy. Now, a team at the University of Hong Kong led by astronomer Jane Lixin Dai is proposing a new method for detecting them. If it works, the approach promises to open a window on the origin of the cosmos itself.
The earliest stars in the Universe formed very soon after the Big Bang. Astronomers call them “Population III” (or Pop III) stars. They’re different from the Sun and other stars in the modern cosmos for a variety of reasons. They formed mainly from the hydrogen and helium in the newborn cosmos. From there, they grew to outrageous sizes and masses very quickly. That growth had a price. Those stars had very short lives because they blew through their core fuels very quickly. However, fusion at their cores and the circumstances of their deaths created the first elements heavier than hydrogen and helium. Those new elements seeded the next generations of stars.
Population III stars were the Universe’s first stars. They were extremely massive, luminous stars, and many of them exploded as supernovae. Image Credit: DALL-ESo, why can’t we detect these early stellar behemoths? For one thing, they existed too far away, too early in history, and their light is very faint. That’s not to say they are undetectable. Astronomers just need advanced methods and technology to spot them.
How to “See” the First StarsProfessor Dai’s team just published a study that suggests a connection between these first stars and nearby black holes. In short, they looked at what happens when a Pop III star interacts with a black hole. Essentially, it gets torn to shreds and gobbled up. For example, the supermassive one at the heart of our Milky Way Galaxy—called Sagittarius A*— does this. It has a regular habit of ripping apart stars that wander too close. When such a tidal disruption event (TDE) happens, it releases huge amounts of radiation. If the same thing happens in another galaxy—no matter how far away—the light from the event is detectable. As it turns out these tidal disruption event flares have interesting and unique properties used to infer the existence of the ancient Pop III stars.
The alien star S0-6 is spiraling toward Sagittarius A*, the Milky Way’s central supermassive black hole. S0-6 likely came from another galaxy and it may get gobbled up or torn up by interactions with the supermassive black hole. Courtesy: Miyagi University of Education/NAOJ.“As the energetic photons travel from a very faraway distance, the timescale of the flare will be stretched due to the expansion of the Universe. These TDE flares will rise and decay over a very long period of time, which sets them apart from the TDEs of solar-type stars in the nearby Universe,” said Dai.
In addition, the expansion of the Universe stretches the wavelengths of light from the flares, according to Dai’s colleague, Rudrani Kar Chowdhury. “The optical and ultraviolet light emitted by the TDE will be transferred to infrared emissions when reaching the Earth,” Chowdhury said. Those emissions are exactly the kind of light new generations of telescopes are built to observe.
Searching for First Stars with Advanced TelescopesThis detection method is right up the alley of the JWST and the upcoming Nancy Grace Roman telescopes. Both are optimized to sense dim, distant objects via infrared wavelengths. They should be able to search out the stretched light from those long-gone Pop III stars unfortunate enough to encounter a black hole. In particular, the Roman telescope will use its wide-field instrument to gather the faint infrared light from stars born at the earliest epochs of cosmic time.
Artist’s impression of the Nancy Grace Roman space telescope (formerly WFIRST). Credit: NASA/GSFCAstronomers generally accept that these first stars formed perhaps as early as a hundred million years after the Big Bang. That’s when overly dense regions filled with hydrogen and helium began to experience gravitational collapse. The stars that formed in those first birth crèches were purely hydrogen and helium—in other words, they were “metal-free”. They lived perhaps a few million years before exploding as cataclysmic supernovae. (By comparison, the Sun has existed for some 4.5 billion years and has another few billion years left before it becomes a red giant and then a white dwarf.) The heavier elements created inside those first stars got blasted out to space, enriching the nearby molecular clouds with infusions of carbon, oxygen, nitrogen, and other elements. Some of the largest first stars could have collapsed directly to form black holes.
Finding these first stars and their emitted light (particularly from possible interactions with early black holes) will give astronomers amazing insight into conditions in the early Universe. Even though those stars are long gone, JWST, Roman, and other telescopes can look back in time and see their dim, infrared light. If Dai’s method works, those telescopes could be responsible for the discovery of tens of Pop III stars each year.
For More InformationHKU Astrophysicists Discover a Novel Method for Hunting the First Stars
Detecting Population III Stars through Tidal Disruption Events in the Era of JWST and RomanNancy Grace Roman Space Telescope
The post A New Way to Search for the First Stars in the Universe appeared first on Universe Today.
NASA Awards Contract for IT Support, Platform Services
NASA has selected CACI, Inc. of Chantilly, Virginia, to maintain and improve IT services across the agency.
The NASA Consolidated Applications and Platform Services (NCAPS) award is a hybrid firm-fixed price and cost-plus-fixed-fee contract with an indefinite delivery/indefinite quantity provision and a maximum potential value of about $2 billion. The performance period will extend eight years with a 90-day phase-in period, followed by a base period, seven option periods, and a six-month extension period.
The NCAPS award will provide a comprehensive enterprise solution to standardize and centralize NASA’s IT services. This includes the maintenance of IT systems, development of new applications as needed for NASA, a rationalization of duplicative efforts to create efficiencies across NASA Centers, and other functions.
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Hubble Finds Surprises Around a Star That Erupted 40 Years Ago
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Hubble Finds Surprises Around a Star That Erupted 40 Years Ago This artist’s concept shows the nova system HM Sagittae (HM Sge), where a white dwarf star is pulling material from its red giant companion. This forms a blazing hot disk around the dwarf, which can unpredictably undergo a spontaneous thermonuclear explosion as the infall of hydrogen from the red giant grows denser and reaches a tipping point. These fireworks between companion stars are fascinating to astronomers by yielding insights into the physics and dynamics of stellar evolution in binary systems. NASA, ESA, Leah Hustak (STScI)
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Astronomers have used new data from NASA’s Hubble Space Telescope and the retired SOFIA (Stratospheric Observatory for Infrared Astronomy) as well as archival data from other missions to revisit one of the strangest binary star systems in our galaxy – 40 years after it burst onto the scene as a bright and long-lived nova. A nova is a star that suddenly increases its brightness tremendously and then fades away to its former obscurity, usually in a few months or years.
Between April and September 1975, the binary system HM Sagittae (HM Sge) grew 250 times brighter. Even more unusual, it did not rapidly fade away as novae commonly do, but has maintained its luminosity for decades. Recently, observations show that the system has gotten hotter, but paradoxically faded a little.
HM Sge is a particular kind of symbiotic star where a white dwarf and a bloated, dust-producing giant companion star are in an eccentric orbit around each other, and the white dwarf ingests gas flowing from the giant star. That gas forms a blazing hot disk around the white dwarf, which can unpredictably undergo a spontaneous thermonuclear explosion as the infall of hydrogen from the giant grows denser on the surface until it reaches a tipping point. These fireworks between companion stars fascinate astronomers by yielding insights into the physics and dynamics of stellar evolution in binary systems.
When I first saw the new data, I went – ‘wow this is what Hubble UV spectroscopy can do!’ – I mean it’s spectacular, really spectacular.Ravi Sankrit
Astronomer
“In 1975 HM Sge went from being a nondescript star to something all astronomers in the field were looking at, and at some point that flurry of activity slowed down,” said Ravi Sankrit of the Space Telescope Science Institute (STScI) in Baltimore. In 2021, Steven Goldman of STScI, Sankrit and collaborators used instruments on Hubble and SOFIA to see what had changed with HM Sge in the last 30 years at wavelengths of light from the infrared to the ultraviolet (UV).
The 2021 ultraviolet data from Hubble showed a strong emission line of highly ionized magnesium that was not present in earlier published spectra from 1990. Its presence shows that the estimated temperature of the white dwarf and accretion disk increased from less than 400,000 degrees Fahrenheit in 1989 to greater than 450,000 degrees Fahrenheit now. The highly ionized magnesium line is one of many seen in the UV spectrum, which analyzed together will reveal the energetics of the system, and how it has changed in the last three decades.
“When I first saw the new data,” Sankrit said, “I went – ‘wow this is what Hubble UV spectroscopy can do!’ – I mean it’s spectacular, really spectacular.”
A Hubble Space Telescope image of the symbiotic star Mira HM Sge. Located 3,400 light-years away in the constellation Sagitta, it consists of a red giant and a white dwarf companion. The stars are too close together to be resolved by Hubble. Material bleeds off the red giant and falls onto the dwarf, making it extremely bright. This system first flared up as a nova in 1975. The red nebulosity is evidence of the stellar wind. The nebula is about one-quarter light-year across. NASA, ESA, Ravi Sankrit (STScI), Steven Goldman (STScI); Image Processing: Joseph DePasquale (STScI)
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With data from NASA’s flying telescope SOFIA, which retired in 2022, the team was able to detect the water, gas, and dust flowing in and around the system. Infrared spectral data shows that the giant star, which produces copious amounts of dust, returned to its normal behavior within only a couple years of the explosion, but also that it has dimmed in recent years, which is another puzzle to be explained.
With SOFIA astronomers were able to see water moving at around 18 miles per second, which they suspect is the speed of the sizzling accretion disk around the white dwarf. The bridge of gas connecting the giant star to the white dwarf must presently span about 2 billion miles.
The team has also been working with the AAVSO (American Association of Variable Star Observers), to collaborate with amateur astronomers from around the world who help keep telescopic eyes on HM Sge; their continued monitoring reveals changes that haven’t been seen since its outburst 40 years ago.
“Symbiotic stars like HM Sge are rare in our galaxy, and witnessing a nova-like explosion is even rarer. This unique event is a treasure for astrophysicists spanning decades,” said Goldman.
The initial results from the team’s research were published in the Astrophysical Journal, and Sankrit is presenting research focused on the UV spectroscopy at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.
The Hubble Space Telescope has been operating for over three decades and continues to make ground-breaking discoveries that shape our fundamental understanding of the universe. Hubble is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope and mission operations. Lockheed Martin Space, based in Denver, Colorado, also supports mission operations at Goddard. The Space Telescope Science Institute in Baltimore, Maryland, which is operated by the Association of Universities for Research in Astronomy, conducts Hubble science operations for NASA.
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NASA’s Webb Opens New Window on Supernova Science
Peering deeply into the cosmos, NASA’s James Webb Space Telescope is giving scientists their first detailed glimpse of supernovae from a time when our universe was just a small fraction of its current age. A team using Webb data has identified 10 times more supernovae in the early universe than were previously known. A few of the newfound exploding stars are the most distant examples of their type, including those used to measure the universe’s expansion rate.
“Webb is a supernova discovery machine,” said Christa DeCoursey, a third-year graduate student at the Steward Observatory and the University of Arizona in Tucson. “The sheer number of detections plus the great distances to these supernovae are the two most exciting outcomes from our survey.”
DeCoursey presented these findings in a press conference at the 244th meeting of the American Astronomical Society in Madison, Wisconsin.
Image A: Jades Deep Field Annotated The JADES Deep Field uses observations taken by NASA’s James Webb Space Telescope (JWST) as part of the JADES (JWST Advanced Deep Extragalactic Survey) program. A team of astronomers studying JADES data identified about 80 objects (circled in green) that changed in brightness over time. Most of these objects, known as transients, are the result of exploding stars or supernovae.
Prior to this survey, only a handful of supernovae had been found above a redshift of 2, which corresponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sample contains many supernovae that exploded even further in the past, when the universe was less than 2 billion years old. It includes the farthest one ever spectroscopically confirmed, at a redshift of 3.6. Its progenitor star exploded when the universe was only 1.8 billion years old.
‘A Supernova Discovery Machine’To make these discoveries, the team analyzed imaging data obtained as part of the JWST Advanced Deep Extragalactic Survey (JADES) program. Webb is ideal for finding extremely distant supernovae because their light is stretched into longer wavelengths — a phenomenon known as cosmological redshift.
Prior to Webb’s launch, only a handful of supernovae had been found above a redshift of 2, which corresponds to when the universe was only 3.3 billion years old — just 25% of its current age. The JADES sample contains many supernovae that exploded even further in the past, when the universe was less than 2 billion years old.
Previously, researchers used NASA’s Hubble Space Telescope to view supernovae from when the universe was in the “young adult” stage. With JADES, scientists are seeing supernovae when the universe was in its “teens” or “pre-teens.” In the future, they hope to look back to the “toddler” or “infant” phase of the universe.
To discover the supernovae, the team compared multiple images taken up to one year apart and looked for sources that disappeared or appeared in those images. These objects that vary in observed brightness over time are called transients, and supernovae are a type of transient. In all, the JADES Transient Survey Sample team uncovered about 80 supernovae in a patch of sky only about the thickness of a grain of rice held at arm’s length.
“This is really our first sample of what the high-redshift universe looks like for transient science,” said teammate Justin Pierel, a NASA Einstein Fellow at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “We are trying to identify whether distant supernovae are fundamentally different from or very much like what we see in the nearby universe.”
Pierel and other STScI researchers provided expert analysis to determine which transients were actually supernovae and which were not, because often they looked very similar.
The team identified a number of high-redshift supernovae, including the farthest one ever spectroscopically confirmed, at a redshift of 3.6. Its progenitor star exploded when the universe was only 1.8 billion years old. It is a so-called core-collapse supernova, an explosion of a massive star.
Image B: Jades Deep Field Transients (NIRCam) This mosaic displays three of about 80 transients, or objects of changing brightness, identified in data from the JADES (JWST Advanced Deep Extragalactic Survey) program. Most of the transients are the result of exploding stars or supernovae. By comparing images taken in 2022 and 2023, astronomers could locate supernovae that recently exploded (like the examples shown in the first two columns), or supernovae that had already exploded and whose light was fading away (third column).
The age of each supernova can be determined from its redshift (designated by ‘z’). The light of the most distant supernova, at a redshift of 3.8, originated when the universe was only 1.7 billion years old. A redshift of 2.845 corresponds to a time 2.3 billion years after the big bang. The closest example, at a redshift of 0.655, shows light that left its galaxy about 6 billion years ago, when the universe was just over half its current age.
Uncovering Distant Type Ia SupernovaeOf particular interest to astrophysicists are Type Ia supernovae. These exploding stars are so predictably bright that they are used to measure far-off cosmic distances and help scientists to calculate the universe’s expansion rate. The team identified at least one Type Ia supernova at a redshift of 2.9. The light from this explosion began traveling to us 11.5 billion years ago when the universe was just 2.3 billion years old. The previous distance record for a spectroscopically confirmed Type Ia supernova was a redshift of 1.95, when the universe was 3.4 billion years old.
Scientists are eager to analyze Type Ia supernovae at high redshifts to see if they all have the same intrinsic brightness, regardless of distance. This is critically important, because if their brightness varies with redshift, they would not be reliable markers for measuring the expansion rate of the universe.
Pierel analyzed this Type Ia supernova found at redshift 2.9 to determine if its intrinsic brightness was different than expected. While this is just the first such object, the results indicate no evidence that Type Ia brightness changes with redshift. More data is needed, but for now, Type Ia supernova-based theories about the universe’s expansion rate and its ultimate fate remain intact. Pierel also presented his findings at the 244th meeting of the American Astronomical Society.
Looking Toward the FutureThe early universe was a very different place with extreme environments. Scientists expect to see ancient supernovae that come from stars that contain far fewer heavy chemical elements than stars like our Sun. Comparing these supernovae with those in the local universe will help astrophysicists understand star formation and supernova explosion mechanisms at these early times.
“We’re essentially opening a new window on the transient universe,” said STScI Fellow Matthew Siebert, who is leading the spectroscopic analysis of the JADES supernovae. “Historically, whenever we’ve done that, we’ve found extremely exciting things — things that we didn’t expect.”
“Because Webb is so sensitive, it’s finding supernovae and other transients almost everywhere it’s pointed,” said JADES team member Eiichi Egami, a research professor at the University of Arizona in Tucson. “This is the first significant step toward more extensive surveys of supernovae with Webb.”
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).
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Media ContactsLaura Betz – laura.e.betz@nasa.gov, Rob Gutro – rob.gutro@nasa.gov
NASA’s Goddard Space Flight Center, Greenbelt, Md.
Ann Jenkins – jenkins@stsci.edu / Christine Pulliam – cpulliam@stsci.edu
Space Telescope Science Institute, Baltimore, Md.
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Take a video tour of Boeing’s Starliner with its 2 NASA astronauts
Landing on Pluto May Only Be A Hop Skip and Jump Away
There are plenty of crazy ideas for missions in the space exploration community. Some are just better funded than others. One of the early pathways to funding the crazy ideas is NASA’s Institute for Advanced Concepts. In 2017 and again in 2021, it funded a mission study of what most space enthusiasts would consider only a modestly ambitious goal but what those outside the community might consider outlandish—landing on Pluto.
Two major questions stand out in the mission design: How would a probe arriving at Pluto slow down, and what kind of lander would be useful on Pluto itself? The answer to the first is one that is becoming increasingly common on planetary exploration missions: aerobraking.
Pluto has an atmosphere, albeit sparse, as confirmed by the New Horizons mission that whizzed past in 2015. One advantage of the minor planet’s relatively weak gravity is that its low-density atmosphere is almost eight times larger than Earth’s, providing a much bigger target for a fast incoming aerobraking craft to aim for.
Fraser discusses future missions to Pluto.Much of the NIAC Phase I project was focused on the details of that aerobraking system, called the Enveloping Aerodynamic Decelerator (EAD). Combined with a lander, that system makes up the “Entrycraft” that the mission is designed around. Ostensibly, it could alternatively contain an orbiter, and there are plenty of other missions discussing how to insert an orbiter around Pluto. Hence, the main thrust of this paper is to focus on a lander.
After aerobraking and slowing down to a few tens of meters a second, from 14 km/s during its interplanetary cruise phase, the mission would drop its lander payload, then rest on the surface, only to rise again under its own power. The answer to the second question of what kind of lander would be useful on Pluto is – a hopper.
Hoppers have become increasingly popular as an exploration tool everywhere, from the Moon to asteroids. Some apparent advantages would include visiting a wide array of interesting scientific sites and not having to navigate tricky land-based obstacles. Ingenuity, the helicopter that accompanied Perseverance paved the way for the idea, but in other words, the atmosphere isn’t dense enough to support a helicopter. So why not use the current favorite method of almost all spacecraft – rockets?
Fraser discusses the results from New Horizons.A hopper would fire its onboard thrusters to reach the area on Pluto’s surface and then land elsewhere. It could then do some science at its new locale before taking off and doing so again somewhere else. The NIAC Phase I Final Report describes five main scientific objectives of the mission, including understanding the surface geomorphology and running some in-situ chemical analysis. A hopper structure would enable those goals much better than a traditional rover at a relatively low weight cost since Pluto’s gravity is so weak.
Other objectives of the report include mathematical calculations of the trajectory, including the aerobraking itself and the stress and strain it would have on the materials used in the system. The authors, who primarily work for Global Aerospace Corporation and ILC Dover, two private companies, also updated the atmospheric models of Pluto with new New Horizons data, which they then fed into the aerobraking model they used. Designing the lander/hopper, integrating all the scientific and navigation components, and estimating their weights were also part of Phase I.
The original launch window for the mission was planned as 2029 back in 2018, though now, despite receiving a Phase II NIAC grant in 2021, that launch window seems wildly optimistic. Since the mission would require a gravity assist from Jupiter, the next potential launch window would be 2042, with a lander finally reaching the surface of Pluto in the 2050s. That later launch window is likely the only feasible one for the mission, so we might have to wait almost 30 years to see if it will come to fruition. Sometimes crazy ideas take patience – we’ll see if the mission team has enough of that to push it onto the surface of one of the most interesting minor planets in the solar system.
Learn More:
B. Goldman – Pluto Hop, Skip, and Jump
UT – NASA is Now Considering a Pluto Orbiter Mission
UT – Should We Send Humans to Pluto?
UT – New Horizons Team Pieces Together the Best Images They Have of Pluto’s Far Side
Lead Image:
Artist’s depiction of the Pluto Lander mission design.
Credit- B. Goldman / Global Aerospace Corporation
The post Landing on Pluto May Only Be A Hop Skip and Jump Away appeared first on Universe Today.
NASA Wallops to Support Sounding Rocket Launch
1 min read
Preparations for Next Moonwalk Simulations Underway (and Underwater) This June 2021 aerial photograph shows the coastal launch range at NASA’s Wallops Flight Facility on Virginia’s Eastern Shore. The Atlantic Ocean is at the right side of this image, and nearby Chincoteague and Assateague islands are at upper left and right, respectively. A subset of NASA’s Goddard Space Flight Center, Wallops is the agency’s only owned-and-operated launch range. Shore replenishment and elevated infrastructure at the range are incorporated into Goddard’s recently approved master plan.Courtesy Patrick J. Hendrickson; used with permission
A suborbital rocket is scheduled for launch the week of June 10-17 from NASA’s launch range at the Wallops Flight Facility in Virginia. This launch is supporting the Missile Defense Agency (MDA), Naval Surface Warfare Center (NSWC), Port Hueneme Division’s White Sands Detachment, other Department of Defense organizations, industry, and academia.
No real-time launch status updates will be available. The launch will not be livestreamed nor will launch status updates be provided during the countdown.
The rocket launch may be visible from the Chesapeake Bay region.
Share Details Last Updated Jun 10, 2024 EditorAmy BarraContactAmy Barraamy.l.barra@nasa.govLocationWallops Flight Facility Related Terms Explore More 1 min read NASA Wallops Visitor Center Extended Hours June 12 Article 7 days ago 4 min read NASA Mission Flies Over Arctic to Study Sea Ice Melt Causes Article 2 weeks ago 2 min read NASA Goddard, Maryland Sign Memo to Boost State’s Aerospace Sector Article 2 weeks agoFood Safety Program for Space Has Taken Over on Earth
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Preparations for Next Moonwalk Simulations Underway (and Underwater) Food for the Apollo astronauts was not always especially appealing, but thanks to the protocol NASA and Pillsbury came up with, known as the Hazard Analysis and Critical Control Point (HAACP) system, it was always safe.Credit: NASA
Countless NASA technologies turn up in our everyday lives, but one of the space agency’s most important contributions to modern society isn’t a technology at all – it’s the methodology that ensures the safety of the food we eat. Today the safety procedures and regulations for most of the food produced around the world are based on a system NASA created to guarantee safe food for Apollo astronauts journeying to the Moon.
For the Gemini missions, NASA and partner Pillsbury tested the food they were producing at the Manned Spacecraft Center, now Johnson Space Center in Houston, and destroyed entire batches when irregularities were found, a process similar to industry practices of the day. In response to agencywide guidelines from the Apollo Program Office aimed at ensuring the reliability of all critical systems, they altered that method for the Apollo missions.
They focused on identifying any points in the production process where hazards could be introduced, establishing procedures to eliminate or control each of those hazards, and then monitoring each of those points regularly. And they required extensive documentation of all this work. This became the foundation for the Hazard Analysis and Critical Control Point (HACCP) system.
The Apollo missions were humans’ longest and farthest voyages in space, so food for the astronauts had to be guaranteed safe for consumption hundreds of thousands of miles from any medical facility. Credit: NASA
Howard Bauman, the microbiologist leading Pillsbury’s Apollo work, convinced his company to adopt the approach, and he became the leading advocate for its adoption across the food industry. That gradual process took decades, starting with the regulation of certain canned foods in the 1970s and culminating in the 2011 Food Safety Modernization Act, which mandated HACCP-like requirements across all food producers regulated by the U.S. Food and Drug Administration. By then, the U.S. Department of Agriculture was managing HACCP requirements for meat and poultry, while Canada and much of Europe had also put similar rules in place.
The standards also apply to any outside producers who want to export food into a country that requires HACCP, effectively spreading them across the globe.
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“Earthrise” by NASA Astronaut Bill Anders
“Earthrise” by NASA Astronaut Bill Anders
NASA astronaut Bill Anders took this iconic image of Earth rising over the Moon’s horizon on Dec. 24, 1968. Anders, lunar module pilot on the Apollo 8 mission, and fellow astronauts Frank Borman and Jim Lovell became the first humans to orbit the Moon and the first to witness the sight pictured.
After becoming a fighter pilot in the Air Force, Anders was selected as an astronaut by NASA. He was backup pilot for the Gemini XI and Apollo 11 flights, and he was lunar module pilot for Apollo 8 – the first lunar orbit mission in December 1968. Anders passed away on June 7, 2024.
Image Credit: NASA