TYB
NASA Astronomy Picture of the Day
March 20, 2025
The Solar Eclipse Analemma Project
Recorded from 2024 March 10, to 2025 March 1, this composited series of images reveals a pattern in the seasonal drift of the Sun's daily motion through planet Earth's sky. Known to some as an analemma, the figure-eight curve was captured in exposures taken on the indicated dates only at 18:38 UTC from the exact same location south of Stephenville, Texas. The Sun's position on the 2024 solstice dates of June 20 and December 21 would be at the top and bottom of the curve and correspond to the astronomical beginning of summer and winter in the north. Points that lie along the curve half-way between the solstices would mark the equinoxes. The 2024 equinox on September 22, and in 2025 the equinox on March 20 (today) are the start of northern fall and spring. And since one of the exposures was made on 2024 April 8 from the Stephenville location at 18:38:40 UTC, this analemma project also reveals the solar corona in planet Earth's sky during a total solar eclipse.
https://apod.nasa.gov/apod/astropix.html
New Bridge Ready to Serve NASA, America’s Space Interests
Mar 19, 2025
The high-rise bridge that serves as the primary access point for employees and visitors to NASA’s Kennedy Space Center in Florida is fully operational.
In the late hours of March 18, 2025, the Florida Department of Transportation (FDOT) opened the westbound portion of the NASA Causeway Bridge, which spans the Indian River Lagoon and connects NASA Kennedy and Cape Canaveral Space Force Station to the mainland.
This new bridge span (right side of photo) sits alongside its twin on the eastbound side, which has accommodated traffic in both directions since FDOT opened it on June 9, 2023.
The new structure replaces the old two-lane drawbridge which operated at that location for nearly 60 years.
“The old drawbridge served us well, witnessing decades of spaceflights since the Apollo era and supporting Kennedy’s transition to a multi-user spaceport,” said Kennedy’s Acting Director Kelvin Manning.
“The new bridge will see NASA send American astronauts back to the Moon and on to Mars, and it will support the continued rapid growth of America’s commercial space industry here at Earth’s premier spaceport.”
At 4,025 feet long, the new NASA Causeway Bridge is about 35% longer than its predecessor, featuring a 65-foot waterway clearance and a channel wide enough to handle larger vessels carrying cargo necessary for Kennedy to continue launching humanity’s future.
The bridge sits on over 1,000 concrete pilings which total more than 22 miles in length.
Nearly 270 concrete I-beams, each weighing hundreds of thousands of pounds, support the bridge, along with over 40,000 cubic yards of concrete and over 8.7 million pounds of steel.
All 110 spans of the old drawbridge were demolished during the construction, with much of the material recycled for future projects.
A $90 million federal infrastructure grant secured in July 2019 by Space Florida via the U.S. Department of Transportation funded nearly 50% of the drawbridge replacement as well the widening of nearby Space Commerce Way.
NASA and the state of Florida provided the remaining funding for the upgrades.
https://www.nasa.gov/image-article/new-bridge-ready-to-serve-nasa-americas-space-interests/
https://www.nasa.gov/missions/swot/next-generation-water-satellite-maps-seafloor-from-space/
https://swot.jpl.nasa.gov/
https://www.science.org/doi/10.1126/science.ads4472
https://www.youtube.com/watch?v=v5GJ4trliE4
Next-Generation Water Satellite Maps Seafloor From Space
Mar 19, 2025
More accurate maps based on data from the SWOT mission can improve underwater navigation and result in greater knowledge of how heat and life move around the world’s ocean.
There are better maps of the Moon’s surface than of the bottom of Earth’s ocean. Researchers have been working for decades to change that.
As part of the ongoing effort, a NASA-supported team recently published one of the most detailed maps yet of the ocean floor, using data from the SWOT (Surface Water and Ocean Topography) satellite, a collaboration between NASA and the French space agency CNES (Centre National d’Études Spatiales).
Ships outfitted with sonar instruments can make direct, incredibly detailed measurements of the ocean floor. But to date, only about 25% of it has been surveyed in this way. To produce a global picture of the seafloor, researchers have relied on satellite data.
Why Seafloor Maps Matter
More accurate maps of the ocean floor are crucial for a range of seafaring activities, including navigation and laying underwater communications cables.
“Seafloor mapping is key in both established and emerging economic opportunities, including rare-mineral seabed mining, optimizing shipping routes, hazard detection, and seabed warfare operations,” said Nadya Vinogradova Shiffer, head of physical oceanography programs at NASA Headquarters in Washington.
Accurate seafloor maps are also important for an improved understanding of deep-sea currents and tides, which affect life in the abyss, as well as geologic processes like plate tectonics.
Underwater mountains called seamounts and other ocean floor features like their smaller cousins, abyssal hills, influence the movement of heat and nutrients in the deep sea and can attract life.
The effects of these physical features can even be felt at the surface by the influence they exert on ecosystems that human communities depend on.
Mapping the seafloor isn’t the SWOT mission’s primary purpose. Launched in December 2022, the satellite measures the height of water on nearly all of Earth’s surface, including the ocean, lakes, reservoirs, and rivers.
Researchers can use these differences in height to create a kind of topographic map of the surface of fresh- and seawater. This data can then be used for tasks such as assessing changes in sea ice or tracking how floods progress down a river.
“The SWOT satellite was a huge jump in our ability to map the seafloor,” said David Sandwell, a geophysicist at Scripps Institution of Oceanography in La Jolla, California.
He’s used satellite data to chart the bottom of the ocean since the 1990s and was one of the researchers responsible for the SWOT-based seafloor map, which was published in the journal Science in December 2024.
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How It Works
The study authors relied on the fact that because geologic features like seamounts and abyssal hills have more mass than their surroundings, they exert a slightly stronger gravitational pull that creates small, measurable bumps in the sea surface above them.
These subtle gravity signatures help researchers predict the kind of seafloor feature that produced them.
Through repeated observations — SWOT covers about 90% of the globe every 21 days — the satellite is sensitive enough to pick up these minute differences, with centimeter-level accuracy, in sea surface height caused by the features below.
Sandwell and his colleagues used a year’s worth of SWOT data to focus on seamounts, abyssal hills, and underwater continental margins, where continental crust meets oceanic crust.
Previous ocean-observing satellites have detected massive versions of these bottom features, such as seamounts over roughly 3,300 feet (1 kilometer) tall.
The SWOT satellite can pick up seamounts less than half that height, potentially increasing the number of known seamounts from 44,000 to 100,000.
These underwater mountains stick up into the water, influencing deep sea currents. This can concentrate nutrients along their slopes, attracting organisms and creating oases on what would otherwise be barren patches of seafloor.
Looking Into the Abyss
The improved view from SWOT also gives researchers more insight into the geologic history of the planet.
“Abyssal hills are the most abundant landform on Earth, covering about 70% of the ocean floor,” said Yao Yu, an oceanographer at Scripps Institution of Oceanography and lead author on the paper.
“These hills are only a few kilometers wide, which makes them hard to observe from space. We were surprised that SWOT could see them so well.”
Abyssal hills form in parallel bands, like the ridges on a washboard, where tectonic plates spread apart.
The orientation and extent of the bands can reveal how tectonic plates have moved over time. Abyssal hills also interact with tides and deep ocean currents in ways that researchers don’t fully understand yet.
The researchers have extracted nearly all the information on seafloor features they expected to find in the SWOT measurements.
Now they’re focusing on refining their picture of the ocean floor by calculating the depth of the features they see.
The work complements an effort by the international scientific community to map the entire seafloor using ship-based sonar by 2030.
“We won’t get the full ship-based mapping done by then,” said Sandwell. “But SWOT will help us fill it in, getting us close to achieving the 2030 objective.”
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https://www.dailymail.co.uk/news/article-14518515/elon-musk-saved-nasa-astronauts-spacex.html
How Elon Musk saved NASA's stranded astronauts with both praising him for the rescue… so why are others not showering SpaceX boss with praise?
Updated: 07:46 EDT, 20 Mar 2025
Elon Musk's Space X safely brought stranded NASA astronauts Butch Wilmore and Suni Williams back down to earth on Tuesday, marking a triumphant conclusion to an eight-day voyage that overran some nine months.
The reaction was jubilant. The astronauts were taken back to Houston for health checks, and NASA confirmed they were 'doing great'. Photographs from Tallahassee showed their pair smiling in stretchers as crews helped them back to dry land.
Wilmore and Williams spent 286 days stranded in space after propulsion issues with their Boeing Starliner craft upended what was supposed to be a week-long stay on the International Space Station.
In a viral clip shared by Elon Musk, the pair took the time to thank the SpaceX boss and President Donald Trump for organising the rescue mission.
'All of us have the utmost respect for Mr Musk and obviously respect and admiration for [the] President of the United States, Donald Trump,' Wilmore said.
'We appreciate them, we appreciate all that they do for us, for human spaceflight, for our nation. And we are thankful that they are in the positions that they are in.'
The story has become a political lightning rod, with President Trump and his close advisor, Elon Musk - who leads SpaceX - repeatedly suggesting former president Joe Biden abandoned the astronauts and refused an earlier rescue plan.
But amid mounting backlash against Trump's cost-cutting tsar over his role in American politics, praise for SpaceX's rescue mission remains muted.
Judging that Musk's politicking had 'poisoned' his business empire, and connecting the recent slump in Tesla value, a guest author for the New York Times offered the damning assessment: 'So what if Elon Musk rescued the astronauts?'
Wilmore and Williams, two veteran NASA astronauts and retired U.S. Navy test pilots, had launched into space as Starliner's first crew in June for what was expected to be an eight-day test mission.
But issues with Starliner's propulsion system led to cascading delays to their return home, culminating in a NASA decision to fold them into its crew rotation schedule and return them on a SpaceX craft this year.
On Tuesday morning, the pair strapped inside their Crew Dragon spacecraft along with two other astronauts and undocked from the ISS at 1.05 a.m. ET (0505 GMT) to embark on a 17-hour trip to Earth.
The four-person crew, formally part of NASA's Crew-9 astronaut rotation mission, plunged through Earth's atmosphere, using its heatshield and two sets of parachutes to slow its orbital speed of 17,000 mph to a soft 17 mph at splashdown, which occurred at 5:57 p.m. ET some 50 miles off Florida's Gulf Coast under clear skies.
'What a ride,' NASA astronaut Nick Hague, the Crew-9 mission commander inside the Dragon capsule, told mission control moments after splashing down. 'I see a capsule full of grins, ear to ear.'
Wilmore and Williams logged 286 days in space on the mission.
The long-awaited return adopted a political bent after capturing the attention of President Trump, who upon taking office in January called for a quicker return of the astronauts and alleged, without evidence, that former President Joe Biden 'abandoned' them on the ISS for political reasons.
NASA officials have said the two astronauts had to remain on the ISS to maintain adequate staffing levels and it did not have the budget or the operational need to send a dedicated rescue spacecraft.
Crew Dragon flights cost between $100 million to $150 million.
SpaceX CEO Elon Musk, now a close advisor to Trump, had echoed the President's call for an earlier return, adding the Biden administration spurned a SpaceX offer to provide a dedicated Dragon rescue mission last year.
NASA acted on Trump's demand by moving Crew-9's replacement mission up sooner, the agency's ISS chief Joel Montalbano said Tuesday.
The agency had swapped a delayed SpaceX capsule for one that would be ready sooner and sped through its methodical safety review process to heed the president's call.
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The Crew Dragon spacecraft used in the rescue is the only U.S. spacecraft capable of flying people in orbit.
Boeing had hoped Starliner would compete with the SpaceX capsule before the mission with Wilmore and Williams threw its development future into uncertainty.
The success of SpaceX's mission was inevitably championed by Elon Musk, who took to his own platform, X, to sing its praises.
'Congratulations to the SpaceX and NASA teams for another safe astronaut return! 'Thank you to POTUS for prioritizing this mission!'
The post had been seen 54 million times at the time of writing, shared 57,000 times and liked by 375,000.
Users noted that NASA had decided to bring the crew home with the SpaceX Crew-9 mission early this year, announced in an August press release published when Biden was president.
'Wilmore and Williams will continue their work formally as part of the Expedition 71/72 crew through February 2025,' the release said
'They will fly home aboard a Dragon spacecraft with two other crew members assigned to the agency's SpaceX Crew-9 mission.'
Starliner, unfit to carry them home, would depart without them and make a controlled re-entry and landing in September 2024.
It was not clear how much faster they returned as a result of the Trump administration's demands to NASA.
While Trump heralded Musk's 'genius' in the recovery, there was muted praise for Elon Musk in the media.
The New York Times went so far as to lead with an opinion piece entitled, 'So What if Elon Musk Rescued the Astronauts?'
Clive Irving wrote in the article that Musk's Tesla had become a 'poisoned brand' amid his 'turn to the hard right', noting the collapse in share price.
'Using his own flippant term, Mr. Musk’s wunderkind status could be experiencing a “rapid unscheduled disassembly.”'
While SpaceX 'eclipsed' Boeing in aerospace, he assessed that Musk's 'innovative willpower can become, in the public eye, as much a liability as an asset'.
Musk finds himself embroiled in a growing firestorm surrounding his involvement in U.S. politics, having taken a role heading the so-called Department of Government Efficiency (DOGE) since Trump came to power.
The world's richest man was widely criticised after he made a gesture interpreted as a Nazi salute at Trump's indoor inauguration parade in Washington D.C. in January.
Musk rattled off a series of off-colour puns on his X account in response, and some conservative politicians in the U.S. and Israel stepped up to defend him.
DOGE has also been the subject of much controversy.
A federal judge ruled Tuesday that the dismantling of USAID likely violated the constitution, indefinitely blocking the department from making further cuts to the agency.
Within weeks, entire government agencies were dismantled and tens of thousands of workers fired.
Critics, including a growing number of U.S. lawmakers, have voiced concerns about potential conflicts of interest between DOGE's decisions and Musk's business interests as CEO of Tesla, SpaceX and X.
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The DOGE team is small, about 40 people, many of them young software engineers who are current and former employees in Musk companies. They have little to no experience inside the U.S. government.
According to its website, the only official window into its operations, DOGE says it had saved U.S. taxpayers $105 billion as of March 2 through a series of actions, including workforce reductions, asset sales, and contract cancellations.
Yet its savings total is unverifiable and its calculations have been riddled with errors and corrections.
In the 'receipts' section of its website, DOGE has repeatedly deleted some of its biggest claims to taxpayer savings. For instance, it reported one $8 billion contract that turned out to be worth only $8 million.
Amid growing outrage, acts of protest have emerged across the world.
On a beach in Wales this week, a silhouette of Musk's controversial gesture appeared in the sand with the words 'Don't buy a Tesla'
British political campaign group Led By Donkeys staged the protest on Black Rock Sands - Traeth y Greigddu - near Porthmadog, Wales.
It was made by attaching a huge rake to the back of a Tesla Model 3, which was driven around the beach to create the 250m x 150m message.
Musk-hating hackers also doxxed Tesla owners in the United States, releasing an interactive map showing their names, addresses, phone numbers and emails.
Musk recently went on FOX, claiming there was a conspiracy to assassinate him and destroy the car company.
He told Sean Hannity on Tuesday that his attempts to cut government waste and fraud is the reason why certain characters 'want to kill me.'
'It turns out when you take away people's, you know, the money that they're receiving fraudulently, they get very upset,' he said.
'And they basically want kill me because I'm stopping their fraud and they want to hurt Tesla because we're stopping the terrible waste and corruption in the government. And, well, I guess they're bad people. Bad people do bad things.'
He repeated claims that there could be left-wing groups 'coordinating' the protests, without providing evidence.
The protests have took a violent turn on Tuesday morning when an arsonist used Molotov cocktails to firebomb five Teslas before firing rounds into the burning vehicles at a dealership in Las Vegas, Nevada.
Last week, roughly 250 activists gathered outside a showroom in New York City, holding anti-Musk placards that read 'Block Fascism Now and 'Musk Must Go' as they shouted 'Elon Musk is not elected! Democracy must be protected!'
The chaos and anger directed at Musk and Tesla have swelled to the point that Trump came out and declared it domestic terrorism.
'They're harming a great American company,' Trump said at the White House, referring to the demonstrators. 'Let me tell you, you do it to Tesla, and you do it to any company, we're going to catch you, and… you're going to go through hell.'
SpaceX's feat to recover the stranded astronauts trapped aboard the ISS is a miracle feat.
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Have a marvelous underground birthday, Barron.
It is also alien abduction day, of all things.
https://worldfrogday.org/
https://nationaltoday.com/alien-abduction-day/
NASA Astronauts Only Get $5 on Top of Salary for Each Day Stuck in Space
Mar 19, 2025 at 7:00 PM EDT
NASA astronauts Barry Wilmore and Sunita Williams won't receive any overtime pay for the extra time they spent at the International Space Station (ISS) after being stuck in space since June.
The Context
Wilmore and Williams arrived home on Tuesday after nine months in space.
Their trip to the ISS was only supposed to last around a week but was extended to more than nine months due to technical issues with Boeing's Starliner spacecraft.
On Sunday, a SpaceX Crew Dragon capsule brought replacement astronauts to the ISS, and Wilmore and Williams were able to return home.
What To Know
Wilmore and Williams launched on what they originally thought was going to be an eight-day mission on June 5, but NASA officials determined it was unsafe for the astronauts to return to Earth in the Starliner due to propulsion issues.
The space agency then had to use an alternative method to bring the astronauts home.
Despite being stuck in space for 278 days longer than originally expected, Wilmore and Williams did not receive overtime pay, a NASA spokesperson told Newsweek.
Standard procedure is that astronauts receive regular, 40-hour workweek salaries when they're aboard the ISS. This does not include any overtime or holiday pay.
But astronauts do receive incidental pay of $5 for each day they spend in space. Since Wilmore and Williams spent 286 days in space, this amounts to $1,430 in incidental pay for each astronaut.
NASA shared several posts on X, formerly Twitter, to document the astronauts' return to Earth on Tuesday. One video shows the spacecraft splashing down into the Atlantic Ocean off the coast of Florida.
Another shows a pod of curious dolphins swimming around the spacecraft shortly after splashdown, providing "extra meaning" to the return home.
What People Are Saying
A NASA spokesperson told Newsweek: "When NASA astronauts are aboard the International Space Station, they receive regular, 40-hour work-week salaries.
They do not receive overtime or holiday/weekend pay. While in space, NASA astronauts are on official travel orders as federal employees, so their transportation, lodging, and meals are provided.
They also are on long-term TDY [temporary duty], and receive the incidentals amount for each day they are in space. Incidental expenses for travel to any location is currently $5 per day."
What Happens Next
The Crew-10 team, which replaced Wilmore and Williams, consists of NASA astronauts Anne McClain and Nichole Ayers, Japanese astronaut Takuya Onishi and Russian cosmonaut Kirill Peskov.
The team is expected to stay at the ISS for six months.
https://www.newsweek.com/nasa-astronauts-only-get-five-dollars-top-salary-stuck-space-2047544
Goodnight, Moon: NASA Cameras on Blue Ghost Capture Lunar Sunset
Mar 19, 2025
This compressed, resolution-limited gif shows the view of lunar sunset from one of the six Stereo Cameras for Lunar-Plume Surface Studies (SCALPSS) 1.1 cameras on Firefly’s Blue Ghost lander, which operated on the Moon’s surface for a little more than 14 days and stopped, as anticipated, a few hours into lunar night.
SCALPSS was taking images every 10 minutes during the sunset. The bright, swirly light moving across the surface on the top right of the image is sunlight reflecting off the lander.
Images taken by SCALPSS 1.1 during Blue Ghost’s descent and landing, as well as images from the surface during the long lunar day, will help researchers better understand the effects of a lander’s engine plumes on the lunar soil, or regolith.
The instrument collected almost 9000 images and returned 10 GB of data. This data is important as trips to the Moon increase and the number of payloads touching down in proximity to one another grows.
The SCALPSS 1.1 project is funded by the Space Technology Mission Directorate’s Game Changing Development program.
SCALPSS was developed at NASA’s Langley Research Center in Hampton, Virginia, with support from Marshall Space Flight Center in Huntsville, Alabama.
https://www.nasa.gov/image-article/goodnight-moon-nasa-cameras-on-blue-ghost-capture-lunar-sunset/
Celestial geometry: satellite shows how the vernal equinox looks from space
March 20, 2025
The European Organization for Satellite Meteorology EUMETSAT published an image taken by the Meteosat-12 satellite on March 20. It demonstrates what the vernal equinox looks like from space.
Equinox is an astronomical phenomenon when the center of the Sun in its apparent motion along the ecliptic crosses the celestial equator.
This moment marks the beginning of astronomical spring in one hemisphere of our planet (in this case the Northern hemisphere) and astronomical autumn in the other hemisphere (in this case the Southern hemisphere).
It is generally believed that during the equinoxes the length of day and night are the same, and the Sun rises exactly in the east and sets exactly in the west.
But this is not entirely true. In fact, during the equinox, the day length is already slightly longer than the night, which is due to atmospheric refraction.
Because of it, at most latitudes the Sun rises not exactly in the east and sets not exactly in the west. The only exception is the equator.
If you go outside the atmosphere and look at the Earth from space on the day of the equinox, you can see a beautiful geometric picture: the terminator line runs along the geographic poles of the Earth and is perpendicular to the Earth’s equator.
It was captured in images taken by the Meteosat-12 satellite on the morning of March 20.
The equinox has another interesting feature that is of interest to amateur astrologers. During it, the magnetic field lines of the Earth and the Sun are temporarily aligned.
This causes even relatively small geomagnetic storms to produce bright auroras that can be seen even at temperate latitudes.
Because of this, March and September are traditionally considered the best months to observe them.
https://universemagazine.com/en/celestial-geometry-satellite-shows-how-the-vernal-equinox-looks-from-space/
https://x.com/ESA_EO/status/1902650726318297200
https://www.livescience.com/physics-mathematics/dark-energy/the-universe-has-thrown-us-a-curveball-largest-ever-map-of-space-reveals-we-might-have-gotten-dark-energy-totally-wrong
https://data.desi.lbl.gov/doc/papers/
'The universe has thrown us a curveball': Largest-ever map of space reveals we might have gotten dark energy totally wrong
March 19, 2025
Astronomers studying the largest-ever map of the cosmos have found hints that our best understanding of the universe is due a major rewrite.
The analysis, which looked at nearly 15 million galaxies and quasars spanning 11 billion years of cosmic time, found that dark energy — the presumed-to-be constant force driving the accelerating expansion of our universe — could be weakening.
Or at least this is what the data, collected by the Dark Energy Spectroscopic Instrument (DESI), suggest when combined with information taken from star explosions, the cosmic microwave background and weak gravitational lensing.
If the findings hold up, it means that one of the most mysterious forces controlling the fate of our universe is even weirder than first thought — and that something is very wrong with our current model of the cosmos.
The researchers' findings were published in multiple papers on the preprint server arXiv and presented March 19 at the American Physical Society's Global Physics Summit in Anaheim, California, so they have not yet been peer-reviewed.
"It's true that the DESI results alone are consistent with the simplest explanation for dark energy, which would be an unchanging cosmological constant," co-author David Schlegel, a DESI project scientist at the Lawrence Berkeley National Laboratory in California, told Live Science.
"But we can't ignore other data that extend to both the earlier and later universe. Combining [DESI's results] with those other data is when it gets truly weird, and it appears that this dark energy must be 'dynamic,' meaning that it changes with time."
The evolving cosmos
Dark energy and dark matter are two of the universe's most puzzling components. Together they make up roughly 95% of the cosmos, but because they do not interact with light, they can't be detected directly.
Yet these components are key ingredients in the reigning Lambda cold dark matter (Lambda-CDM) model of cosmology, which maps the growth of the cosmos and predicts its end.
In this model, dark matter is responsible for holding galaxies together and accounts for their otherwise inexplicably powerful gravitational pulls, while dark energy explains why the universe's expansion is accelerating.
But despite countless observations of these hypothetical dark entities shaping our universe, scientists are still unsure where they came from, or what they even are.
Currently, the best theoretical explanation for dark energy is made by quantum field theory, which describes the vacuum of space as filled with a sea of quantum fields that fluctuate, creating an intrinsic energy density in empty space.
In the aftermath of the Big Bang, this energy increases as space expands, creating more vacuum and more energy to push the universe apart faster.
This suggestion helped scientists to tie dark energy to the cosmological constant — a hypothetical inflationary energy, growing with the fabric of space-time throughout the universe's life. Einstein named it Lambda in his theory of general relativity.
"The problem with that theory is that the numbers don't add up," said Catherine Heymans, a professor of astrophysics at the University of Edinburgh and the Astronomer Royal for Scotland who was not involved in the study.
"If you say: 'Well, what sort of energy would I expect from this sort of vacuum?' It's very, very, very, very different from what we measure," she told Live Science.
"It's kind of exciting that the universe has thrown us a curveball here," she added.
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Scanning the dark universe
To figure out if dark energy is changing over time, the astronomers turned to three years' worth of data from DESI, which is mounted on the Nicholas U.
Mayall 4-meter Telescope in Arizona. DESI pinpoints the monthly positions of millions of galaxies to study how the universe expanded up to the present day.
By compiling DESI's observations, which includes nearly 15 million of the best measured galaxies and quasars (ultra-bright objects powered by supermassive black holes), the researchers came up with a strange result.
Taken on their own, the telescope's observations are in "weak tension" with the Lambda-CDM model, suggesting dark energy may be losing strength as the universe ages, but without enough statistical significance to break with the model.
But when paired with other observations, such as the universe's leftover light from the cosmic microwave background, supernovas, and the gravitational warping of light from distant galaxies, the likelihood that dark energy is evolving grows.
In fact, it pushes the observations' disagreement with the standard model as far as 4.2 Sigma, a statistical measure on the cusp of the five-Sigma result physicists use as the "gold standard" for heralding a new discovery.
Related: After 2 years in space, the James Webb telescope has broken cosmology. Can it be fixed?
Whether this result will hold or fade over time with more data is unclear, but astrophysicists are growing confident that the discrepancy is less likely to disappear.
"These data seem to indicate that either dark energy is becoming less important today, or it was more important early in the universe," Schlegel said.
Astronomers say that further answers will come from a flotilla of new experiments investigating the nature of dark matter and dark energy in our universe.
These include the Euclid space telescope, NASA's Nancy Grace Roman Space Telescope, and DESI itself, which is now in its fourth of five years scanning the sky and will measure 50 million galaxies and quasars by the time it's done.
"I think it's fair to say that this result, taken at face-value, appears to be the biggest hint we have about the nature of dark energy in the [rough] 25 years since we discovered it," Adam Riess, a professor of astronomy at Johns Hopkins University who won the 2011 Nobel Prize in physics for his team's 1998 discovery of dark energy, told Live Science.
"If confirmed, it literally says dark energy is not what most everyone thought, a static source of energy, but perhaps something even more exotic."
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Hegseth Says Air, Space Forces Key to Deterring, Engaging in Future Conflicts
March 19, 2025
Defense Secretary Pete Hegseth said today that the Air Force and Space Force will be instrumental in both deterring and engaging in future military conflicts.
He remarked on the value of the two service branches while speaking at the Department of the Air Force Summit — a gathering of senior leadership from across each force — held at Joint Base Andrews, Maryland.
"The future of deterrence … for this nation truly does reside in this room," Hegseth told those in attendance.
"It's our airpower, the next generation of it and our ability to project it that will be the decisive factor in whether or not we truly deter our peer [adversaries] of the 21st century," he continued.
In reference to the threat posed by China, Hegseth told the senior leaders in the room that the decisions they make and the manner in which they implement, utilize and match threats to capabilities will determine whether "we live in a [century] dominated by the U.S. or dominated by the Chinese."
"I hope that is the sense of urgency that exists in this room; it's certainly what we think about every day in the secretary's office," he said.
When asked for his thoughts on the future of the space domain, Hegseth said it was the domain of the future.
"I feel like there's no way to ignore the fact that the next and the most important domain of warfare will be the space domain. …
So, you're going to see far more investment from this administration into that domain, both offensively and defensively … because that's where we can continue to maintain an advantage," Hegseth said.
He added that, in war-gaming simulations, the outcomes have often been affected by the space domain-related capabilities each side of the competition had at their disposal.
"There are strategic things that can be done that change the entire [warfighting] calculus that no one else is paying attention to, and I would anticipate that [the space domain] is one of those for us," Hegseth said.
Toward the end of his appearance at the summit, Hegseth was asked about the Defense Department's recent efforts to realign its budget with national security priorities and whether those efforts would result in significant changes.
"I think we spend a lot of time — understandably and correctly so — talking about efficiencies, talking about [the Department of Government Efficiency], talking about audits [and] talking about reprioritizations, and we're going to keep doing that because we need to be good stewards of the taxpayer dollars," Hegseth said.
"But [President Donald J. Trump] has repeatedly said that we're going to rebuild [the military] … and the Air Force will be a huge part of how that [military] gets funded," he added.
https://www.defense.gov/News/News-Stories/Article/Article/4127637/hegseth-says-air-space-forces-key-to-deterring-engaging-in-future-conflicts/
'Molecular library' opens up new frontier of biological space-time
March 19, 2025
In the search for solutions to diseases like cancer, scientists are pursuing a new frontier in biology—the spatial and temporal places where our cells live.
Where first generation drugs targeted single molecules, over time evolving their own resistance, new tools and techniques are needed to keep ahead of resistant diseases by targeting the surrounding cellular space.
Much of this exploration is taking place at the surface of our cells—the protein-packed semi-permeable membranes that act as protectors and as signaling posts to other cells in the surrounding area.
Over 60% of current market drugs target our membrane proteins, and this number is expected to increase with the help of a new, accessible molecular "library" developed by Yale's Kallol Gupta, an assistant professor of Cell Biology at the School of Medicine.
"There are all kinds of proteins congregating at the cellular membrane, and if we want to understand what a protein does, how it's regulated by its environment, and specifically how it triggers the spread of a disease, we need to understand what surrounds it," explained Gupta, whose lab is part of the Nanobiology Institute at Yale's West Campus.
Lacking the spatial nanotechnology required to understand the molecular context of how membrane proteins are regulated in health and diseases, the scholars developed a novel platform that provides access to around 2,000 membrane proteins as well as a chemical tool to examine areas that surround proteins of interest.
"We wanted to share these important tools to study membrane proteins and make them accessible to researchers anywhere in the world," said Caroline Brown, a graduate student in the Gupta lab and a co-first author of the study, which appears in Nature Methods. "There are thousands of proteins in our body, but which one should you look at relative to a specific disease?"
The new database is expected to save time by helping any researcher trying to find proteins that relate to a specific health problem.
Collaborating with adjacent labs at the West Campus, the scholars used on-site mass spectrometry to reveal a class of molecules known to be active in the cell membrane.
With the "library" established, the scholars turned to developing a new tool that could make sense of the broader cellular space.
Typically measured at the micron level—or slightly thinner than a spider web—for the library to reveal events and associations driving protein signaling, resolutions of a thousand-fold higher would be needed.
"By modulating the chemistry of the molecules, we were able to change the diameter of the area of interest to create a new spatial resolution that helps us understand how the function of a protein is regulated by its surroundings," continued Gupta.
The result is what the scientists refer to as a programmable chemical "scoop" used to collect molecular information from a given nanoscale contextual area.
The technological landmark is expected to help more scientists understand how membrane proteins interact in association with other proteins, in turn revealing new drug targets to disrupt the spatial signals that drive different diseases.
https://phys.org/news/2025-03-molecular-library-frontier-biological-space.html
https://www.nature.com/articles/s41592-024-02517-x
Astronomers discover 'space tornadoes' around the Milky Way's core
March 19, 2025
Swirling through the Milky Way's central zone, in the turbulent region surrounding the supermassive black hole at the core of our galaxy, dust and gases constantly churn as energetic shock waves ripple throughout. An international team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have sharpened our view of this action by a factor of 100, discovering a surprising new filamentary structure in this mysterious region of space.
Although the galaxy's central molecular zone (CMZ) has long been known to be a region filled with swirling dust and gas molecules cycling through formation and destruction, the mechanism that drives this process has remained elusive.
Molecules serve as tracers for various processes in molecular clouds, with silicon monoxide (SiO) being particularly useful in detecting the presence of shock waves.
Using ALMA's high resolution and sensitivity to map distinct spectral lines within the molecular clouds at the center of the Milky Way, an international team of astronomers led by Kai Yang of the Shanghai Jiao Tong University has delineated a new type of long, narrow filamentary structure at a significantly finer scale.
The dynamic interaction between this turbulent environment and the slim filaments produced as shocks ripple through provides a more complete view of the cyclical processes within the CMZ.
"When we checked the ALMA images showing the outflows, we noticed these long and narrow filaments spatially offset from any star-forming regions. Unlike any objects we know, these filaments really surprised us. Since then, we have been pondering what they are," Yang summarized.
These "slim filaments" were an unexpected, serendipitous find in the emission lines of SiO and eight other molecules. Their line-of-sight velocities are coherent and are inconsistent with outflows.
Thus, they do not fit the profile of other, previously discovered types of dense gas filaments; furthermore, the filaments show no association with dust emission, and they do not appear to be in hydrostatic equilibrium.
"Our research contributes to the fascinating Galactic Center landscape by uncovering these slim filaments as an important part of material circulation," summarizes Xing Lu, a research professor at Shanghai Astronomical Observatory and a corresponding author of the research paper.
"We can envision these as space tornados: they are violent streams of gas, they dissipate quickly, and they distribute materials into the environment efficiently."
It remains unknown how these slim filaments initially arise, but shock processes emerge as a likely explanation, Yang's team reports.
This inference is based on several key observations: the rotational transition of SiO 5-4 clearly seen in ALMA observations, the presence of CH3OH masers, and the relative abundances of complex organic molecules in these slim filaments.
"ALMA's high angular resolution and extraordinary sensitivity were essential to detect these molecular line emissions associated with the slim filaments, and to confirm that there is no association between these structures with dust emissions," emphasized Yichen Zhang, a professor at Shanghai Jiao Tong university and a corresponding author of the research paper. "Our discovery marks a significant advancement, by detecting these filaments on a much finer 0.01 parsec scale to mark the working surface of these shocks."
This breakthrough offers a more detailed view of the dynamic processes occurring in the CMZ, and suggests a cyclical process of material circulation.
First, shocks act as a mechanism to create these slim filaments, releasing SiO and several complex organic molecules such as CH3OH, CH3CN, and HC3N into the gas phase and into the interstellar medium.
Then, the slim filaments dissipate to refuel the widespread shock-released material in the CMZ. Finally, the molecules freeze back into dust grains, resulting in a balance between depletion and replenishment.
Assuming that the slim filaments exist throughout the CMZ as abundantly as in this sample, there would be a cyclical balance between depletion and replenishment.
"SiO is currently the only molecule that exclusively traces shocks, and the SiO 5-4 rotational transition is only detectable in shocked regions that have both relatively high densities and high temperatures.
This makes it a particularly valuable tool for tracing shock-induced processes in the dense regions of the CMZ," Yang said.
https://phys.org/news/2025-03-astronomers-space-tornadoes-milky-core.html
https://www.aanda.org/articles/aa/full_html/2025/02/aa53191-24/aa53191-24.html
What were Stephen Hawking's greatest contributions to science?
March 19, 2025
Famed physicist Stephen Hawking took gravity to its ultimate limits. In doing so, he made a number of significant advancements in our understanding of black holes, cosmology and quantum gravity.
Plus, his contributions to the popularization of science cement his legacy for generations to come.
Hawking began his research career in the 1960s, well before his diagnosis with ALS (amyotrophic lateral sclerosis) led him to use a wheelchair and communicate through technology rather than his voice for most of his adult life.
Although it's impossible to neatly summarize Hawking's 200-plus academic papers spanning more than four decades, he was deeply interested in the nature of gravity in extreme environments.
This started with the nature of singularities. Hawking took mathematician and physicist Roger Penrose's proof that singularities do exist in general relativity and extended it to the universe as a whole — proving that, in our models of the evolution of the cosmos, the Big Bang really did begin with a singularity, a point of infinite density.
Hawking then went on to explore black holes in more depth and arrived at his surprising conclusion that black holes aren't entirely black.
By artfully combining general relativity with quantum mechanics, Hawking found that black holes emit a tiny amount of radiation, which means they can evaporate and disappear.
Hawking extended this idea to formulate a set of laws of black hole thermodynamics — versions of the familiar laws of thermodynamics but applied to black holes — suggesting a deep link between the nature of heat, energy and entropy with that of gravity.
Back in the cosmological realm, Hawking made major advances in understanding how inflation worked. Although Alan Guth originated the idea that the early universe underwent a period of exceptionally rapid expansion, it was Hawking who fleshed it out and made it a powerful, robust theory of the cosmos.
Besides inflation, Hawking spent a lot of time examining the earliest moments of the Big Bang. He was especially interested in the question of the "beginning” — did the universe have a beginning?
Did it even make sense to ask that question? What did quantum mechanics have to say about that?
Gravity is the story of space-time, and Hawking spent many years investigating the deep relationship between space, time and quantum mechanics.
For example, he worked a lot on wormholes — shortcuts through space-time — and probed whether they were physically possible.
Realizing that wormholes could also be used as time machines, he proposed the chronology protection conjecture, which states that time travel into the past is forbidden because the past has already happened and cannot be changed.
Unlike many of his colleagues, Hawking was not particularly interested in the development of a theory of everything, an all-encompassing set of equations that could explain all of physics.
Although he dabbled in aspects of string theory — a promising candidate for a theory of everything — he largely focused on the nature of gravity.
But his work on the quantum aspects of gravity reverberated throughout the entire community. For example, any theory of everything must be able to explain the riddle posed by Hawking radiation, or the slippery nature of cosmic inflation.
Hawking's work opened a window into the unification of quantum mechanics and gravity — a goal that researchers are still trying to follow through with today.
To give some perspective on the magnitude of Hawking's work, consider the Nobel prize.
The 2019 Nobel Prize in physics was awarded "for contributions to our understanding of the evolution of the universe and Earth's place in the cosmos," with one-half to James Peebles "for theoretical discoveries in physical cosmology."
Hawking died in 2018, but if he had lived, his contributions to cosmology would have made him a contender for sharing the prize.
The 2020 Nobel Prize in physics was divided, with one-half awarded to Roger Penrose "for the discovery that black hole formation is a robust prediction of the general theory of relativity.”
Hawking could have been a contender here too, for his insight into the fundamental nature of black holes.
Hawking had a decent chance of being in the running for two separate Nobel prizes, which definitely puts him in rare company.
Besides that prodigious scientific output, Hawking was a prolific science communicator. His 1988 book "A Brief History of Time" became an instant hit.
It was many people's first introduction to quantum mechanics, gravity and cosmology. He became a cultural icon, with almost everybody able to recognize him and his computerized voice.
All of these contributions, without a doubt, make for a legacy worth remembering.
https://www.space.com/the-universe/what-were-stephen-hawkings-greatest-contributions-to-science
That would be a twist alright