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Ozempic and Wegovy linked to lower risk of alcoholism
Ozempic and Wegovy linked to lower risk of alcoholism
New space stations exhibit invites public to find 'Home Beyond Earth'
How Magic Tricks Help Us Understand Animal Minds
By performing tricks for birds, monkeys and other creatures, researchers hope to learn how they perceive and think about their world
Astronomers Should Take a Deeper Look at Naming
We should—and must—take careful measure of what we name cosmic objects and the terms we use throughout science
What Do Google’s AI Answers Cost the Environment?
Google is bringing AI answers to a billion people this year, but generative AI requires much more energy than traditional keyword searches
China's Chang'e 6 mission carried a stone flag to the moon's far side
The first stars in the universe could have formed surprisingly early
The first stars in the universe could have formed surprisingly early
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
The post Webb Sees Asteroids Collide in Another Star System appeared first on Universe Today.
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.
Get breaking news, images, and features from the space station on the station blog, Instagram, Facebook, and X.
Learn more about International Space Station research and operations at:
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Josh Finch / Claire O’Shea
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202-358-1100
joshua.a.finch@nasa.gov / claire.a.o’shea@nasa.gov
Leah Cheshier / Anna Schneider
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leah.d.cheshier@nasa.gov / anna.c.schneider@nasa.gov
'Star Trek V: The Final Frontier' at 35: Did William Shatner direct the cheesiest chapter in the franchise?
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.
For information about NASA and other agency programs, visit:
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Tiernan Doyle
Headquarters, Washington
202-774-8357
tiernan.doyle@nasa.gov
Jan Wittry
Glenn Research Center, Cleveland
216-433-5466
jan.m.wittry-1@nasa.gov
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.
For information about NASA and other agency programs, visit:
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Tiernan Doyle
Headquarters, Washington
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tiernan.doyle@nasa.gov