Astronomy

Cut marks on a 4000-year-old skull suggest ancient Egyptian doctors tried to treat a man with nasopharyngeal cancer

Cut marks on a 4000-year-old skull suggest ancient Egyptian doctors tried to treat a man with nasopharyngeal cancer

Video: 00:02:36

ESA’s EarthCARE satellite lifted off on a SpaceX Falcon 9 rocket from the Vandenberg Space Force Base in California, US, on 29 May at 00:20 CEST (28 May, 15:20 local time).

Developed as a cooperation between ESA and the Japan Aerospace Exploration Agency (JAXA), the Earth Cloud Aerosol and Radiation Explorer satellite carries a set of four instruments to make a range of different measurements that together will shed new light on the role that clouds and aerosols play in regulating Earth’s climate.

It’s coming back! Sunspot AR3664 gave us an amazing display of northern lights in mid-May and it’s now rotating back into view. That means another great display if this sunspot continues to flare out. It’s all part of solar maximum—the peak of an 11-year cycle of solar active and quiet times. This cycle is the result of something inside the Sun—the solar dynamo. A team of scientists suggests that this big generator lies not far beneath the solar surface. It creates a magnetic field and spurs flares and sunspots.

For a long time, solar physicists thought the magnetic dynamo was deep inside the Sun. That view may change thanks to work by researchers at MIT, the University of Edinburgh, the University of Colorado, Bates College, Northwestern University, and the University of California. The dynamo may be related to instabilities in what’s called the “near-surface shear layer” in the Sun’s outermost regions. The activities in this layer result in the flares and sunspots we see more of as the Sun nears “solar maximum”. Flares are high-energy outbursts while sunspots are surface features with local magnetic fields. Sunspots are relatively cool regions on the solar surface and occur in 11-year cycles.

NASA’s Solar Dynamics Observatory captured these images of the solar flares — as seen in the bright flashes in the upper right — on May 5 and May 6, 2024. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in teal. The loops are magnetic field lines channeling plasma. Credit: NASA/SDO

“The features we see when looking at the Sun, like the corona that many people saw during the recent solar eclipse, sunspots, and solar flares, are all associated with the sun’s magnetic field,” said MIT researcher Keaton Burns. “We show that isolated perturbations near the sun’s surface, far from the deeper layers, can grow over time to potentially produce the magnetic structures we see.”

How is the Sun’s Magnetic Field Connected to Activity?

To understand the magnitude of this finding, let’s look at the structure of the Sun. We all know the Sun is a superheated ball of plasma. So, how does boiling plasma create a magnetic dynamo? “One of the basic ideas for how to start a dynamo is that you need a region where there’s a lot of plasma moving past other plasma and that shearing motion converts kinetic energy into magnetic energy,” Burns explained. “People had thought that the Sun’s magnetic field is created by the motions at the very bottom of the convection zone.”

The interior structure of our Sun. The dynamo generating a magnetic field could lie very close to the solar surface. Credit: Kelvin Ma, via Wikipedia

Of course, pinning down the exact location of the solar dynamo in the upper layers is difficult. Simulations can only go so far, and modeling the plasma flow throughout the entire Sun is a massive computing task. So, Burns and the team decided simulate a smaller piece of the Sun. They studied the stability of plasma flow near the solar surface. That required helioseismology data showing vibrations on the Sun’s surface, which allowed them to determine the average flow of plasma in that region. “If you take a video of a drum and watch how it vibrates in slow motion, you can work out the drumhead’s shape and stiffness from the vibrational modes,” said Burns. “Similarly, we can use vibrations that we see on the solar surface to infer the average structure on the inside.”

Think of the Sun as layered like an onion. Different plasma layers rush past each other as the Sun rotates, according to Burns. “Then we ask: Are there perturbations, or tiny changes in the flow of plasma, that we could superimpose on top of this average structure, that might grow to cause the sun’s magnetic field?”

Computing an Answer

The team developed algorithms that they incorporated into a numerical framework called the Dedalus Project. They looked for self-reinforcing changes in the Sun’s average surface flows. The algorithm discovered new patterns that could grow and result in realistic solar activity. Interestingly, those patterns also match the locations and timescales of sunspots. It turns out that certain changes in the flow of plasma at the very top of the Sun’s surface layers generate magnetic structures. This isn’t a new idea. Burns pointed out that the conditions there resembled the unstable plasma flows in accretion disks around black holes. Accretion disks are massive collections of gas and stellar dust that rotate in towards a black hole. They’re driven by “magnetorotational instability,” which generates turbulence in the flow and causes it to fall inward.

Burns and the team thought this phenomenon at a black hole might also be at work inside our Sun. They suggest that magnetorotational instability in the Sun’s outermost layers could be the first step in generating its magnetic field. “I think this result may be controversial,” he said. “Most of the community has been focused on finding dynamo action deep in the Sun. Now we’re showing there’s a different mechanism that seems to be a better match to observations.”

Implications of the New Model

Not only will the team’s work help solar physicists understand the creation of the magnetic dynamo, but may give them insight into other solar phenomena. In particular, a dynamo in the upper 10 percent of the Sun may explain things like the Maunder Minimum. This was a period between 1645 to 1715 when there were very few sunspots. In some years, observers saw no sunspots at all. In other years, they observed fewer than 20. Astronomers did chart the 11-year sunspot cycle through that time, so the Sun wasn’t entirely inactive.

If the Sun’s magnetic dynamo operates in its outermost layers, the science of solar activity forecasting could get a big boost. Right now, it’s difficult to tell when a flare might break out. Flares and coronal mass ejections like those that contributed to the May 10-11 geomagnetic storm can damage satellites and telecommunications systems here on Earth. In addition, power grids and other technology are at risk. In the long run, however, gaining new understanding of the Sun’s dynamo is a big deal.

“We know the dynamo acts like a giant clock with many complex interacting parts,” says co-author Geoffrey Vasil, a researcher at the University of Edinburgh. “But we don’t know many of the pieces or how they fit together. This new idea of how the solar dynamo starts is essential to understanding and predicting it.”

For More Information

The Origin of the Sun’s Magnetic Field Could Lie Close to Its Surface
The Solar Dynamo Begins Near the Surface

The post The Sun’s Magnetic Field Might Only Be Skin Deep appeared first on Universe Today.

Start talking about Venus and immediately my mind goes to those images from the Venera space probes that visited Venus in the 1970’s. They revealed a world that had been scarred by millennia of volcanic activity yet as far as we could tell those volcanoes were dormant. That is, until just now.  Magellan has been mapping the surface of Venus and between 1990 and 1992 had mapped 98% of the surface. Researchers compared two scans of the same area and discovered that there were fresh outflows of molten rock filling a vent crater! There was active volcanism on Venus. 

Venus is the second planet from the Sun and similar in size to Earth, the similarities end there though. It has a thick atmosphere that is toxic to life as we know it, there is sulphuric acid rain high in the atmosphere and a surface temperature of almost 500 degrees. When the Venera probes visited they measured an atmospheric pressure of around 90 times that at the Earth’s surface. Combined with the other hostile properties of the atmosphere, a human visitor would not survive long. 

Venus

The dense atmosphere of Venus is largely the result of volcanic activity. Over the millennia, there have been extensive volcanic eruptions that pumped carbon dioxide into the atmosphere. The lack of bodies of water on Venus meant the built up carbon dioxide in the atmosphere didn’t get absorbed. In addition to this, the lack of a magnetic field meant the solar wind – the pressure from the Sun – drove away the lighter elements leaving behind the thick, carbon dioxide rich atmosphere we see today. But the volcanoes that drove the atmospheric changes are thought to have been extinct for a long time. 

It’s not just the Venera probes that have been exploring Venus. In 1980, the Magellan spacecraft was launched by NASA to map the surface of the hottest planet in the Solar System. On arrival, it was put into a polar orbit and used radar to penetrate the thick clouds. Back in 2023, a study of some of the Magellan images from the synthetic aperture radar showed changes to a vent near the summit of Maat Mons. It was the first direct evidence of an eruption on the surface of Venus and changes in the lava flows. 

The surface of Venus captured by a Soviet Venera probe. Credit: Russian Academy of Sciences / Ted Stryk

In the latest study that was published in Nature Astronomy, more data from the synthetic aperture radar was studied. The team focussed on Sif Mons and Niobe Planitia and the data that had been collected from both areas in 1990 and again in 1992. The data revealed stronger radar returns in the later set of data suggesting new rock formations from volcanic activity. The team did consider it may have been caused by some other phenomena such as sand dunes or atmospheric effects but altimeter data confirmed the presence of new solidified lava. 

The team were able to use lava flows on Earth as a comparison to help understand the new flows on Venus. They estimated that the new flows are between 3 and 20 metres deep. They could go a step further though and estimated that the eruption at Sif Mons produced about 30 square kilometres of rock which would be enough to fill over 36,000 swimming pools.  The eruption at Niobe Planitia produced even more with an estimated 45 square kilometres of rock..

Studying volcanic activity on Venus helps to understand not just the geological processes but also helps to understand the structure of the interior too. This can help inform the likelihood of habitability for future explorers. None of which would have been possible without the recent volcanic activity to help us probe further the secrets of Venus.

Source: Ongoing Venus Volcanic Activity Discovered With NASA’s Magellan Data

The post Volcanoes Were Erupting on Venus in the 1990s appeared first on Universe Today.

ESA’s EarthCARE satellite, poised to revolutionise our understanding of how clouds and aerosols affect our climate, has been launched. This extraordinary satellite embarked on its journey into space on 29 May at 00:20 CEST (28 May, 15:20 local time) aboard a Falcon 9 rocket from the Vandenberg Space Force Base in California, US.

Russia's uncrewed Progress 86 cargo craft departed the International Space Station early Tuesday morning (May 28), ending a six-month orbital stay.

The largest camera ever built for astronomy arrived in Chile, where it will be installed atop Rubin Observatory's Simonyi Survey Telescope.

Venus may be as geologically active as Earth, with volcanoes possibly spewing on its surface in the present day.

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We’re fortunate to live in these times. Multiple space telescopes feed us a rich stream of astounding images that never seems to end. Each one is a portrait of some part of nature’s glory, enriched by the science behind it all. All we have to do is revel in the wonder.

The ESA’s Euclid space telescope is the latest one to enrich our inboxes. It was launched on July 1st, 2023, and delivered its first images in November of that year. Now, we have five new images from Euclid, as well as the first science results from the wide-angle space telescope.

“They give just a hint of what Euclid can do.”

Valeria Pettorino, ESA’s Euclid Project Scientist.

The images demonstrate the telescope’s power and its ability to address some of the deepest questions we have about the Universe. They are also impressive because of their visual richness and because they took only 24 hours of the telescope’s expected six years of observing time.

“Euclid is a unique, ground-breaking mission, and these are the first datasets to be made public – it’s an important milestone,” says Valeria Pettorino, ESA’s Euclid Project Scientist. “The images and associated science findings are impressively diverse in terms of the objects and distances observed. They include a variety of science applications, and yet represent a mere 24 hours of observations. They give just a hint of what Euclid can do. We are looking forward to six more years of data to come!”

The leading image is the most stunning and perhaps the most relatable. It shows Messier 78, aka NGC 2068. It’s a reflection nebula and star-forming region contained in the vast Orion B molecular cloud complex. Euclid used its infrared capabilities to see through the dust that shrouds the star-formation region. It’s given us our most detailed look at the filaments of gas and dust that give the region its ghostly appearance.

Euclid can detect objects that are just a few times more massive than Jupiter, an impressive feat. In its M78 image, it found over 300,000 objects in that mass range.

This zoomed-in portion of Euclid’s M78 image shows the depth the telescope’s images deliver. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi. LICENCE CC BY-SA 3.0 IGO

One of Euclid’s objectives is to study dark matter and how it’s distributed in the Universe. It uses gravitational lensing to probe dark matter, and its image of the Abell 2390 galaxy cluster exhibits the tell-tale curved arcs of light coming from distant background objects created by gravitational lensing. The image also shows more than 50,000 galaxies.

Euclid’s image of the Abell 2390 cluster of galaxies contains over 50,000 galaxies. It also shows the intracluster light that comes from individual stars torn from their galaxies and sitting in intergalactic space. These stars can help astrophysicists determine where dark matter is. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi.
LICENCE: CC BY-SA 3.0 IGO

Most of the stars currently forming in the Universe are forming in spiral galaxies. Euclid captured this image of NGC 6744 as an archetype of that galaxy type. The telescope’s wide-angle lens and depth of field capture the entire galaxy and also small details. It shows lanes of dust that emerge as spurs on the spiral arms.

With this image, astronomers can map individual stars and the gas that feeds their formation. They can also identify globular clusters and new dwarf galaxies. Euclid already found one new dwarf galaxy astronomers have never seen before, which is impressive for a galaxy that’s already been studied so intently.

Euclid’s complete image of NGC 6744 is on the left, and a zoomed-in portion is on the right. NGC 6744 is one of the largest spiral galaxies outside our region of space. The telescope’s detailed image will let astronomers count and map individual stars and the gas that feeds star formation. Star formation is how galaxies evolve, so studying NGC 6744’s star formation activity feeds into a greater understanding of galaxy evolution. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi. LICENCE: CC BY-SA 3.0 IGO

Euclid also imaged another galaxy cluster, Abell 2764. This cluster contains hundreds of galaxies within a halo of dark matter. Euclid’s impressive wide-field view comes into play in this image. Not only does it show Abell 2764 in the image’s upper right, but it also shows other clusters that are even more distant, multiple background galaxies, and interacting galaxies with their streams of stars.

In this image, Euclid captured galaxy cluster Abell 2764 and the wider region surrounding it. Abell 2764 is in the upper right corner. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi LICENCE CC BY-SA 3.0 IGO

The image highlights one of Euclid’s other capabilities. The foreground star is in our own galaxy, and when viewed with a telescope, its diffuse light creates a halo that obscures distant objects behind it. Euclid was built to minimize that diffuse halo effect. The disturbance from the star’s diffuse light is minimal, meaning Euclid can see distant background objects near the star’s line of sight.

This pair of zoomed-in images of Abell 2764 shows Euclid’s power. On the left is the foreground star. These stars can create halos of diffuse light that obscure other objects, but Euclid is built to minimize the effect. On the right is a zoom-in of Abell 2764 itself, with multitudes of background galaxies. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi. LICENCE: CC BY-SA 3.0 IGO

The final of the five new images is of galaxies in the Dorado Group. Euclid’s image shows signs of galaxies merging. The Dorado Group is a relatively young group, and many of its member galaxies are still forming stars. The image helps astronomers study how galaxies form and evolve inside halos of dark matter.

The Dorado Group is one of the richest galaxy groups in the southern hemisphere. Euclid’s wide and deep images give astronomers their best look at it. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi. LICENCE: ESA Standard Licence

A zoomed-in image shows more detail of the main pair of galaxies in the image. Euclid’s unique large field-of-view and high spatial resolution means that for the first time, astronomers can use the same instrument and observations to deeply study tiny objects the size of star clusters, intermediate objects like the central regions of galaxies, and larger features like tidal tails in one large region of the sky.

“The beauty of Euclid is that it covers large regions of the sky in great detail and depth, and can capture a wide range of different objects all in the same image – from faint to bright, from distant to nearby, from the most massive of galaxy clusters to small planets.”

ESA Director of Science, Prof. Carole Mundell

Prior to Euclid, astronomers had to use small chunks of data to painstakingly catalogue globular clusters around galaxies. But Euclid’s wide images capture far more data in a single image, simplifying the task. Globular clusters provide important clues to how galaxies evolve over time.

This zoom-in shows a pair of interacting galaxies in the Dorado Group. Tidal tails of stars are visible as wispy streams near the right and bottom right of the right-side galaxy. Image Credit: ESA/Euclid/Euclid Consortium/NASA, image processing by J.-C. Cuillandre (CEA Paris-Saclay), G. Anselmi. LICENCE: ESA Standard Licence

Euclid’s mission is only starting. The telescope’s images so far have no equivalent, and there’s much more to come. Euclid hasn’t even begun its main survey yet. That survey will comprise both a wide survey covering about 15,000 square degrees of the sky and a deep survey covering about 50 square degrees.

“It’s no exaggeration to say that the results we’re seeing from Euclid are unprecedented,” says ESA Director of Science, Prof. Carole Mundell. “Euclid’s first images, published in November, clearly illustrated the telescope’s vast potential to explore the dark Universe, and this second batch is no different.”

“The beauty of Euclid is that it covers large regions of the sky in great detail and depth, and can capture a wide range of different objects all in the same image – from faint to bright, from distant to nearby, from the most massive of galaxy clusters to small planets,” said Mundell. “We get both a very detailed and very wide view all at once. This amazing versatility has resulted in numerous new science results that, when combined with the results from Euclid’s surveying over the coming years, will significantly alter our understanding of the Universe.”

The scientific papers released with these images are available here.

The post Enjoy Five New Images from the Euclid Mission appeared first on Universe Today.

Astronaut Eugene A. Cernan, lunar module pilot, egresses the Apollo 10 spacecraft during recovery operations in the South Pacific. U.S. Navy underwater demolition team swimmers assisted in the recovery operations. Already in the life raft were astronauts Thomas P. Stafford (left), commander; and John W. Young, command module pilot. The three crewmen were picked up by helicopter and flown to the prime recovery ship, USS Princeton.

SpaceX launched the EarthCARE mission this afternoon (May 28) after sending aloft a group of Starlink internet satellites this morning.

The European Space Agency has now released ten images from its dark universe detective spacecraft, Euclid. We asked scientists from various fields to pick their favorite Euclid image thus far.

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ESA and some of its member states have signed the non-binding Zero Debris Charter, committing themselves to take steps to help tackle the orbital debris problem.