A new space-based telescope aims to address a key solar mystery.
A new experiment will explore a region of the Sun that’s tough to see from the surface of the Earth. The solar corona—the elusive, pearly white region of the solar atmosphere seen briefly during a total solar eclipse—is generally swamped out by the dazzling Sun. Now, the Coronal Diagnostic Experiment (CODEX) will use a coronagraph to create an ‘artificial eclipse’ in order to explore the poorly understood middle corona region of the solar atmosphere.
CODEX launched as part of the cargo manifest on SpaceX’s Cargo Dragon this week, on mission CRS-31. CRS-31 arrived at the ISS and docked at the Harmony forward port of the station on November 5th.
CODEX is a partnership between NASA’s Goddard Spaceflight Center, Italy’s National Institute for Astrophysics (INAE) and KASI (Korea Astronomy and Space Science Institute). Technical expertise for the project was provided by the U.S. Naval Research Laboratory (NRL).
CODEX will be mounted on the EXPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier Site 3 (ELC-3) on the ISS.
An animation of CODEX on the ISS. NASA Why Use CoronagraphsCoronagraphs work by blocking out the Sun with an occulting disk. The disk used in CODEX is about as wide as an orange. Though coronagraphs can work on Earth, placing them in space is an easy way to eliminate unwanted light due to atmospheric scattering.
The solar corona, as imaged by the High Altitude Observatory’s coronagraph. UCAR/NCAR.Targeting the middle region of the corona is crucial, as it’s thought to be the source of the solar wind. But what heats this region to temperatures actually hotter than the surface below? This rise is in the order of a million degrees, versus 6000 degrees Celsius for the solar photosphere. The same unknown process accelerates particles to tremendous speeds of over a million kilometers an hour.
CODEX seeks to address this dilemma, and will measure Doppler shifts in charged particles at four filtered wavelengths. The instrument will need to center and track the Sun from its perch on the exterior of the ISS. To this end, this must occur while speeding around the Earth once every 90 minutes. CODEX will be able to see the Sun roughly half of the time, though seasons near either solstice will allow for near-continuous views.
CODEX will work with NASA’s Parker Solar Probe and ESA’s Solar Orbiter (SolO) in studying this coronal heating dilemma. In addition, it will also join the Solar Heliospheric (SOHO’s) LASCO C2 and C3 coronagraph in space. Another new coronagraph instrument in space is the National Oceanic Atmospheric Administration’s CCOR-1 (Compact Coronagraph) aboard the GOES-19 satellite in geosynchronous orbit.
A Solar Wind Riddle“CODEX measures the plasma’s temperature, speed and density around the whole corona between 3 and 10 solar radii, and will measure how those parameters evolve in time, providing new constraints on all theories of coronal heating,” Niicholeen Viall (GFSC-Solar Physics Laboratory) told Universe Today. “Parker Solar Probe measures these plasma parameters in the upper corona (getting as close as 10 solar radii) in great detail, but it makes those measurements in situ (from one one location in space and time) and only briefly that close to the Sun.”
The CODEX team with the instrument, ahead of launch. Credit: CODEX/NASA.The goal of CODEX is to provide a holistic view of solar wind activity. “In contrast, CODEX provides a global view and context of these plasma parameters and their evolution,” says Viall. “Additionally, CODEX extends the measurements much closer to the Sun than Parker Solar Probe (PSP), linking the detailed measurements made at PSP at 10 solar radii through the middle corona, down to ~3 solar radii, closer to their source. This is important because most of the coronal heating has already taken place by 10 solar radii, where PSP measures.”
A Dual MysteryTwo theories vie to explain the solar heating mystery. A first says that tangled magnetic fields are converted into thermal power. These are in turn fed into the corona as bursts of energy. Another says that oscillations known as Alfvén waves inject energy in a sort of feedback loop in the lower corona.
“Solar Orbiter has (an) EUV (Extreme ultraviolet) and white light imager that could be used to connect the CODEX measurements to their sources on the Sun,” says Viall.
Understanding this region and the source of the solar wind is crucial to predicting space weather. This is especially vital when the Sun sends powerful corona mass ejections our way. Not only can these spark low latitude aurorae, but these can also impact communications and pose a hazard to satellites and astronauts in space.
“CODEX is similar to all coronagraphs, in that they block light out from the photosphere to see the much fainter corona.” Says Viall. CODEX’s field of view has overlap with, but is different than SOHO’s coronagraphs and CCOR. The largest difference though, is that CODEX has special filters that can provide the temperature and speed of the solar wind, in addition to the density measurements that white light coronagraphs always make.”
The Past (and Future) of Coronagraphs in SpaceFurthermore, there’s also a history of coronagraphs aboard space stations. This goes all the way back to the white-light coronagraph aboard Skylab in the early 1970s.
Looking to the future, more coronagraphs are headed space-ward. ESA’s solar-observing Proba-3 launches at the end of November. Proba-3 will feature the first free-flying occulting disk as part of the mission. PUNCH (the Polarimeter to UNify the Corona and Heliosphere) will feature four micro-sat orbiters. The mission will rideshare launch with NASA’s SPHEREx mission early next year.
“PUNCH is a white light coronagraph and set of heliospheric imagers that together image from six solar radii out through the inner heliosphere.” Says Viall. PUNCH will be able to watch the structures that CODEX identifies as they as they evolve and are modulated father out in the heliosphere.”
Fianlly, astronomers can also use coronagraph-style instruments to image exoplanets directly. The Nancy Grace Roman Space telescope (set to launch in 2027) will feature one such instrument.
It will be exciting to see CODEX in action, as it probes the mysteries of the solar wind.
The post CODEX Coronagraph Heads to the ISS on Cargo Dragon appeared first on Universe Today.
We are in dire need of photos, dear readers. If you have good wildlife snaps, please send them in. Thanks! Today we have a contribution on falconry (or rather, “hawkery”) from ecologist Susan Harrison of UC Davis. Her notes and captions are indented, and you can enlarge the photos by clicking on them.
Hunting with the Sky Wolves
One sunny October morning, I accompanied two expert falconers and their Harris’s Hawks (Parabuteo unicinctus) on a jackrabbit (Lepus californicus) hunt. I’d met Don and Pete when they displayed their hawks at at a native seed farm open house last spring. As leaders of the California Hawking Club they work to educate the public about falconry. It’s a demanding and highly regulated sport, practiced by only about 4,000 licensed falconers in the US. Here is poignant advice from the CHC’s website: “Will you, can you, commit part of your waking hours to a creature who at the very best of times will merely tolerate your presence, is as affectionate as a stone, and at the worst of times will cause you heartache and puncture wounds?”
Harris’s Hawks are favored for falconry because they are unusually social raptors. Uniquely, they hunt in groups and have thus been nicknamed “wolves of the sky.” Our expedition involved a trio of different-aged siblings, although Harris’s Hawks need not be kin to hunt together.
Released from their travel crates, Jenny, Zeva, and Shooter quickly flew to a power line and began scouting the fields:
Jenny wears orange jesses (leg straps). Note that she also sports a GPS transmitter, as do the other hawks, enabling the falconers to follow them on foot guided by a smartphone app. Unlike true falcons, Harris’s Hawks do not typically fly many miles in the course of a hunt.
Jenny:
Cooperative hunting by the ‘wolves of the sky’ is thrilling to watch. The hawk who first spots the prey chirps to alert the other hawks and initiates the chase. (If the falconers happen to see the animal first, they helpfully call ‘hoo-hoo-hoo’ to the hawks.) The other hawks then see the speeding prey and fly ahead, coordinating their paths to intercept it. Female Harris’s Hawks are larger than males and will often make the killing pounce.
The first rabbit was killed so quickly that we didn’t see it happen. Don and Pete bagged the rabbit so the hunt could continue. Note the hawks resting in the shade at lower left:
The falconers then raised a T-perch and two hawks hopped aboard, allowing them to sit and look for prey as the group moved around. As we traversed orchards and fields, the hawks frequently came and went from the perch, as well as pausing in trees:
A second rabbit soon rocketed out of the orchard, which was a fatal decision on its part. Moving far faster than me or my camera, the hawk trio took it to the ground a few hundred yards away:
After handing the hawks meat treats from a bag, Don took the rabbit to the car to serve up lunch:
Spritzing their meal with water helps the hawks stay hydrated:
The hawk on the left, Abby, is a young trainee on a lightweight tether called a creance. She didn’t get to hunt this time, but did get to join in the feast:
Their hunt and meal finished, the hawks permitted themselves to be returned to their travel crates:
The rewards of being a falconer, again from the CHC website:
“Are you ready to be one of that elite band of hunters in the most awesome sport on the face of the earth? Are you ready to have people see you with awe, amazement and sometimes anger? Are you ready to be the absolute center of attention whenever you carry your hawk on your fist? Are you ready for that incredible rush when that wild creature first returns to you, on its own and able to fly free but decides to come to you instead?”
Some falconers and their birds are not sport hunters but pest-control professionals, whose job is to keep away nuisance birds such as starlings. The most famous of these is Rufus the Hawk, who for 16 years has kept pigeons off the Wimbledon tennis courts.
Rufus the Hawk (from The Telegraph; photo credit: Getty):
Australia is planning a total ban on social media for children under 16 years old. Prime Minister Anthony Albanese argues that it is the only way to protect vulnerable children from the demonstrable harm that social media can do. This has sparked another round of debates about what to do, if anything, about social media.
When social media first appeared, there wasn’t much discussion or recognition about the potential downsides. Many viewed it as one way to fulfill the promise of the web – to connect people digitally. It was also viewed as the democratization of mass communication. Now anyone could start a blog, for example, and participate in public discourse without having to go through editors and gatekeepers or invest a lot of capital. And all of this was true. Here I am, two decades later, using my personal blog to do just that.
But the downsides also quickly became apparent. Bypassing gatekeepers also means that the primary mechanism for quality control (for what it was worth) was also gone. There are no journalistic standards on social media, no editorial policy, and no one can get fired for lying, spreading misinformation, or making stuff up. While legacy media still exists, social media caused a realignment in how most people access information.
In the social media world we have inadvertently created, the people with the most power are arguably the tech giants. This has consolidated a lot of power in the hands of a few billionaires with little oversight or regulations. Their primary tool for controlling the flow of information is computer algorithms, which are designed to maximize engagement. You need to get people to click and to stay on your website so that you can feed them ads. This also created a new paradigm in which the user (that’s you) is the product – apps and websites are used to gather information about users which are then sold to other corporations, largely for marketing purposes. In some cases, like the X platform, and individual can favor their own content and perspective, essentially turning a platform into a propaganda machine. Sometimes an authoritarian government controls the platform, and can push public discourse in whatever direction they want.
Perhaps worse, if the only feedback loop for algorithms is engagement, then this creates an interesting psychological experiment. What drives engagement is extremism, outrage, and reinforcing prejudices. This has resulted in a few derivative phenomena, including echochambers. It became trivial, and almost automatic, for spaces to emerge on social media that reinforce a particular world view. Those who do not comply are deemed “trolls” and are banned. Rather than having a shared reality of core facts, people are largely isolated in cocoons of ideological purity. The result was increasing division – each half of the country (politically speaking) cannot imagine how the other half can possibly believe what they do.
In addition getting people to engage meant feeding them increasingly radical content, which had the result of radicalizing a lot of people. This resulted in the rise of lunatic ideas like flat-eatherism, and conspiracy theories like QAnon. It also supercharged the spread of misinformation, and provided a convenient mechanism for the deliberate spread of disinformation. Bad actors and authoritarian governments quickly seized upon this opportunity.
There is also another layer here -mental health. Obsessively engaging online results in fomo, bullying, low self-esteem, and depression. This is exacerbated by the fact that the layer of protection afforded by social media allows for psychopaths, predators, and other bad actors to roam freely.
So I can understand the feeling that by allowing young children to engage on social media is like throwing our children to the wolves, with predictable negative effects. But the question remains – what do we do about it? Australia is planning an experiment of their own, taking a bold step to outright ban social media use for children under 16. There is already a lot of pushback against this idea. In an open letter from 100 academics, they argue that banning is a blunt tool, and that it will leave children more vulnerable. They will not learn the skills to be able to navigate social media, they argue. They suggest that other methods would be better, without getting into too much detail about what those methods might be. The details of the banning also have to be worked out – how will it be enforced?
It is a genuine dilemma. There is no real solution, only different trade-offs. It is certainly worth having the conversation about what the options and trade-off might be. Doing nothing is one option – just let the experiment play itself out, with the idea that society will adapt. While I think this will happen to some degree, we may not like where we end up. My problem with this approach is that it assumes that things will play out organically. Rather, powerful actors (tech giants, powerful corporations, and governments) will exploit the system to their own advantage and to the detriment of the public. We may have just provided the tools for authoritarian governments to exert ultimate control over society. It may not be a coincidence that democracies are in retreat around the world.
But even without an authoritarian thumb on the scale, misinformation seems to have a significant advantage in the world of social media. Perhaps even worse, we seem to be heading for a world in which truth is irrelevant. I spend a lot of time on TikTok, for example, trying to spread a little science and critical thinking. The platform has lots of good science communication on hit, and lots of wholesome entertainment. But it is also overwhelmed with nonsense, including misinformation and disinformation. But perhaps the dominant trend is for something that is not so much misinformation but that is completely unconcerned with reality. Many videos are purely performative, to the point that I cannot figure out if the person making the video actually believes anything they say. It’s as if it doesn’t matter – it’s all about engagement. The very concept that one factual claim may be more reliable than an opposing claim seems anathema. It’s all opinion, and all that matters is clicks. Any argument otherwise is immediately dismissed as a conspiracy, or mere elitism.
We may already be living in the post-truth hellscape that critics predicted social media would lead to. I don’t think a ban is likely to be the solution, but I welcome the experiment. If Australia enacts the ban, we need to pay close attention to what results. Even if there are some net positive outcomes, it is not likely to be the only needed solution. We need to start talking more seriously about what measures should be taken to reign in some of the worse aspects of social media. Also AI is about to supercharge everything, giving even more power spreaders of misinformation. I liken to an industry that is dumping tons of toxic substances into the environment. I don’t think we should just sit back and see what happens.
The post The Social Media Dilemma first appeared on NeuroLogica Blog.
Doctors who are concerned about members of our profession enabling powerful anti-vaxx disinformation agents should speak up before it's too late. But its probably too late already.
The post Robert Kennedy Jr. & His Doctor Friends May Just Be Getting Started first appeared on Science-Based Medicine.Mars’ ancient climate is one of our Solar System’s most perplexing mysteries. The planet was once wet and warm; now it’s dry and cold. Whatever befell the planet, it didn’t happen all at once.
New research shows that on ancient cold Mars, sheets of frozen carbon dioxide allowed rivers to flow and a sea the size of the Mediterranean to exist.
Mars’ climatic change from warm and wet to cold and dry wasn’t abrupt. There was no catastrophic impact or other triggering event. Throughout its gradual shift, there were different climatic episodes.
The planet’s surface is characterized by features that indicate water’s presence. River channels, impact craters, and basins that were once paleolakes illustrate Mars’ complex climatic history. Mars is much different from Earth, but they both follow the same set of natural rules.
In Earth’s frigid climates, rivers can flow underneath thick, protective ice sheets. New research shows that a similar thing happened on Mars. The research is published in JGR Planets and is titled “Massive Ice Sheet Basal Melting Triggered by Atmospheric Collapse on Mars, Leading to Formation of an Overtopped, Ice-Covered Argyre Basin Paleolake Fed by 1,000-km Rivers.” The lead author is Peter Buhler, a Research Scientist at the Planetary Science Institute.
The research examines a period about 3.6 billion years ago when Mars was likely transitioning from the Noachian Period to the Hesperian Period. At that time, most of the surface water was frozen into large ice sheets in Mars’ southern region, according to the research. The planet’s CO2 atmosphere suffered periodic collapses, and sublimated out of the atmosphere. Those collapses formed a layer of CO2 650 meters (0.4 miles) thick that created a massive ice cap over the South Pole. It insulated the 2.5-mile-thick (4 km) layer of frozen water that made up the ice sheets.
This simple schematic from the research shows how the proposed model works. When the CO2 atmosphere collapses and sublimates, it forms an insulating layer over the frozen water in Mars’ southern polar regions. The meltwater is released and flows across the surface, insulated by a layer of frozen water. Image Credit: Buhler, 2024.Buhler modelled how the CO2 cap acted as a thermal blanket and showed that it released massive amounts of meltwater from the frozen pole. This water flowed down rivers, with the top layers freezing and insulating the liquid water underneath.
“You now have the cap on top, a saturated water table underneath and permafrost on the sides,” Buhler said. “The only way left for the water to go is through the interface between the ice sheet and the rock underneath it. That’s why on Earth you see rivers come out from underneath glaciers instead of just draining into the ground.”
According to Buhler’s work, enough water was liberated to fill the Argyre Basin.
The Argyre Basin is one of the largest impact basins on the planet, measuring roughly 1800 km (1100 mi) in diameter. This massive impact basin was formed billions of years ago by a comet or asteroid striking Mars. It drops about 5.2 km (3.2 mi) below the surrounding plains, making it the second deepest basin on Mars. Scientists have long thought that the basin once held water—as much as the Mediterranean Sea—and Buhler’s work shows how it may have filled.
“Eskers are evidence that at some point there was subglacial melt on Mars, and that’s a big mystery,” Buhler said. Eskers are long stratified ridges of sand and gravel deposited by meltwater streams that flow under glaciers. They’re common on Earth, where glaciers once covered the surface. Mars’ eskers support the idea that the same thing happened on that planet.
These are eskers in western Sweden. They were created by water flowing under a glacier. When the glacier retreated, they were left as evidence. The same likely happened on Mars. Image Credit: By Hanna Lokrantz – https://www.flickr.com/photos/geologicalsurveyofsweden/6853882122/in/album-72157625612122901/, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=42848874The subglacial rivers would have flowed underneath the ice, where they were insulated from the cold. When they exited the glacier, they would have oozed along until a thick enough ice cap formed to insulate them. Buhler says that the ice would’ve grown until it was hundreds of meters thick, and the water flowing under the ice caps would’ve been several feet deep. The water would’ve carved out river channels thousands of miles long, and there are several of those that go from the polar cap to the Argyre Basin.
This figure shows the polar cap, the Argyre Crater, and the long sinuous channels that carried meltwater from the cap to the basin. Image Credit: Buhler 2024.“People have been trying to discover processes that could make that happen, but nothing really worked,” Buhler said. “The current best hypothesis is that there was some unspecified global warming event, but that was an unsatisfying answer to me, because we don’t know what would have caused that warming. This model explains eskers without invoking climatic warming.”
Argyre Basin is massive and voluminous, and proposed explanations for how it was filled with water were left wanting. It has approximately the same volume as the Mediterranean Sea. Buhler’s model shows that it took about ten thousand years for the basin to fill, and after it filled, the water emptied into plains about 8,000 km (5,000 miles) away.
This process happened repeatedly over a one-hundred-million-year era, with each event separated by millions of years.
“This is the first model that produces enough water to overtop Argyre, consistent with decades-old geologic observations,” Buhler said. “It’s also likely that the meltwater, once downstream, sublimated back into the atmosphere before being returned to the south polar cap, perpetuating a pole-to-equator hydrologic cycle that may have played an important role in Mars’ enigmatic pulse of late-stage hydrologic activity. What’s more, it does not require late-stage warming to explain it.”
Buhler’s work is supported by other research. “Previous literature supports the presence of a ~0.6 bar (atmospheric) CO2 inventory, as utilized in the model, near the Noachian-Hesperian boundary,” he writes in his research. The history of Mars’ atmospheric pressure is backed up by cosmochemistry, mineralogy, atmosphere and meteorite trapped-gas isotopic ratios, geomorphology, and extrapolations of modern-day atmospheric escape.
“Thus, there is strong evidence that Mars had a sufficiently large mobile CO2 reservoir to drive the atmospheric-collapse-driven melting scenario described in this manuscript, with collapse occurring at a time commensurate with Valley Network formation during Mars’ intense, Late Noachian/Early Hesperian terminal pulse of intense fluvial activity,” Buhler writes.
That period of Mars’ history stands out as its own distinct phase of geological activity, whereas changes were more gradual in the earlier Noachian Period. The Late Noachian/Early Hesperian saw intense valley network formation. Many of these valleys are deeply carved into the landscape, often cutting through older geological features. That suggests that the water flow was powerful and erosive. This fluvial activity also created large deposits of sediment, like the ones NASA’s Perseverance Rover is exploring in Jezero Crater.
Jezero Crater on Mars. Scientists think that the sediments in the crater may be one km deep. Image Credit: NASA/JPL-Caltech/ASUBuhler’s research is partly based on modern-day observations of Mars’ atmospheric CO2 and its cycles. Much of it is actually frozen and bound to the regolith. Mars’ rotational tilt shifts over a 100,000-year timeline. When it’s closer to straight up and down, the Sun hits the equator, and CO2 is released from the regolith into the atmosphere. It eventually reaches the poles, where it’s frozen into the caps.
When Mars is tilted, the poles are warmed, and the CO2 sublimates and is released into the atmosphere again. It eventually reaches the now-cooler regolith, which absorbs it. “The atmosphere is mostly just along for the ride,” Buhler said. “It acts as a conduit for the real action, which is the exchange between the regolith and the southern polar ice cap, even today.”
Buhler is still working with his model and intends to continue testing it more rigorously. If it successfully withstands more testing, our understanding of Mars will take a big leap forward.
The post Flowing Martian Water was Protected by Sheets of Carbon Dioxide appeared first on Universe Today.
Space debris, which consists of pieces of spent rocket stages, satellites, and other objects launched into orbit since 1957 – is a growing concern. According to the ESA Space Debris Office, there are roughly 40,500 objects in LEO larger than 10 cm (3.9 inches) in diameter, an additional 1.1 million objects measuring 1 and 10 cm (0.39 to 3.9 inches) in diameter, and 130 million objects 1 mm to 1 cm (0.039 to 0.39 inches). The situation is projected to worsen as commercial space companies continue to deploy “mega-constellations” of satellites for research, telecommunications, and broadband internet services.
To address this situation, researchers from the University of Kyoto have developed the world’s first wooden satellite. Except for its electronic components, this small satellite (LingoSat) is manufactured from magnolia wood. According to a statement issued on Tuesday, November 5th, by the University of Kyoto’s Human Spaceology Center, the wooden satellite was successfully launched into orbit atop a SpaceX Falcon 9 rocket from NASA’s Kennedy Space Center in Florida. This satellite, the first in a planned series, is designed to mitigate space debris and prevent what is known as “Kessler Syndrome.”
In 1978, NASA scientists Donald J. Kessler and Burton G. Cour-Palais proposed a scenario in which the density of objects in Low Earth Orbit (LEO) would become high enough that collisions between objects would cause a cascade effect. This would lead to a vicious cycle in which collisions caused debris, which would make further collisions more likely, leading to more collisions and more debris (and so on). For decades, astronomers and space agencies have feared that we are approaching this point or will be shortly.
Animation of Kyoto University’s prototype wooden satellite in space. Credit: Kyoto UniversityBy manufacturing satellites out of wood, the University of Kyoto scientists expect they will burn up when they re-enter Earth’s atmosphere at the end of their service. This will prevent potentially harmful metal particles from being generated when a retired satellite returns to Earth. The small satellite measures just 10 cm (4 in) on a side and weighs only 900 grams, making it one of the lightest satellites ever sent to space. Its name comes from the Latin word for wood (“lingo”) and CubeSat, a class of small satellites with a form factor of 10 cm cubes.
Before launch, the science team installed LingoSat in a special container prepared by the Japan Aerospace Exploration Agency (JAXA). According to a spokesperson for Sumitomo Forestry, LignoSat’s co-developer, the satellite will “arrive at the ISS soon and will be released to outer space about a month later.”
Once the satellite reaches the ISS, it will dock via the Kibo Japanese Experiment Module (JEM) before deployment. It will then spend the next six months in space, and data will be sent from the satellite to researchers who will monitor it for signs of strain. Ultimately, the goal is to determine if wooden satellites can withstand the extreme temperature changes and conditions in space. A second satellite, LingoSat 2, is a double-unit CubeSat currently scheduled for launch in 2026.
Further Reading: The Guardian
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