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Unravelling the complex biological process that allows fish to regrow injured fins could help advance regenerative medicine in humans

Fishers in Albania caught a blue shark with an 18-centimetre fragment of swordfish bill embedded in its skull, in the first known case of a shark surviving such an injury

Highlights from 18 years of the Skeptoid podcast.

A new program has simulated multiple satellites, collecting images of a cloud from many angles at the same time, which could help us to better understand what's happening inside the cloud.

A new program has simulated multiple satellites, collecting images of a cloud from many angles at the same time, which could help us to better understand what's happening inside the cloud.

The hits just keep on coming from the Mars Perseverance rover. It’s exploring Jezero Crater on the Red Planet, looking for evidence of microbial life in the planet’s ancient (or even recent) past. Recently it spotted a very strange-looking rock with black and white stripes. Its appearance and location sparked a lot of questions. Perseverance team members have named it “Freya Castle.”

From the image, this chunk looks remarkably similar to metamorphic rocks on Earth. The most familiar are gneiss, marble, and schist (to name a few). According to Jeffrey Kargel of the Planetary Science Institute, who speculated on what Freya Castle could be, it resembles a very high-grade type of rock similar to what we find here at home. “It looks like and plausibly is, a metamorphic rock containing feldspar or other white-ish minerals arranged in something called boudinage,” he said. “That word stems from French, relating to a chain-link sausage-like structure. In the case of rocks, it forms when you have layered material, usually sedimentary rocks, where the layers are compressed from above under conditions of high heat and pressure. Much of the rock responds plastically squishing down and spreading out.”

Kargel, who is not associated with the Perseverance mission, pointed out that the conditions under which Freya Castle formed on Mars would be similar to Earth’s. “Those conditions have been common on Earth, and erosion then eventually exposes the rocks at the surface. If this is an indigenous Mars rock, it likely would have undergone metamorphism in the lower crust, and then an impact blasted it out, and the rock landed where the rover could examine it,” he said. Other transport possibilities include a deposit by fluid delivery, which makes sense since water has flooded the crater in the past.

An example of gneiss metamorphic rock from Sabino Canyon, in Arizona (USA) as a comparison to the Freya Castle rock on Mars. Courtesy Jeffrey Kargel, PSI. What Kind of Rock Is It?

So, what’s the story with this rock? Based on the image, it looks pretty out of context with much of the dust and sedimentary material in the crater. That makes it worth reviewing the region in a bit more detail. An impact some 3.8 billion years ago carved out Jezero Crater. It lies on the western edge of a large impact basin called Isidis Planitia. A large impact created that basin during an impact about 3.9 billion years ago. At some point in the distant past, water filled Jezero at least twice. There’s a river delta as well as flow channels exiting the crater.

Sedimentary rocks as seen by Perseverance rover at “Enchanted Lake” in Jezero Crater on Mars. Courtesy: NASA/JPL-Caltech

Where there’s water, there’s sediment, which hardens into sedimentary rock. ( The main types of rock are igneous (volcanic or intrusive in origin), sedimentary (deposited by wind or water), and metamorphic.) Not surprisingly, the Perseverance rover continues to find sedimentary deposits and layers at Jezero. The delta is clay-rich, and the crater contains other materials known to be in contact with water. However, some of the rocks in Jezero are also igneous. That means they were created by volcanic activity and somehow brought to the crater.

NASA’s Perseverance rover, which is searching for signs of ancient life on Mars. Some of the rocks in this image are volcanic in origin. (credit: NASA/JPL-Caltech/MSSS)

That brings us back to Freya Castle, which looks metamorphic at first glance. Such rocks have experienced some kind of heat, pressure, or other kinds of geologic stress. That process changed them from one type to another. It also altered the texture of the original rock and the mineral composition.

Creating a Metamorphic Rock

On Earth, metamorphics are a large part of our planet’s crust. They can form deep under the surface where temperatures and pressures are high. Tectonic activity also forces metamorphism. So do impact events. Both heat and compress the surrounding rock. An impact also “excavates” rocks out from deep beneath the surface and tosses them across the surface. Volcanism could be another culprit, sending hot magma into cracks and openings of existing rocks and “morphing” them. Metamorphism can also be the product of the action of hot, mineral-rich fluid injected into other rocks by hydrothermal activity. If that happened, the fluids could have found their way into the layers. The result would be deposits of “intrusive” minerals, resulting in a layered look.

An example of folded metamorphic rock from Norway. Courtesy Siim Sepp, CC BY_SA 3.0

On Mars, all these processes also occurred throughout history. A good analysis of the rock’s minerals could give more details about the mineral makeup of Freya Castle. That would settle the question of what kind of rock it is. Such studies could also give some insight into conditions on Mars at the time it formed.

One thing to keep in mind is that Perseverance looked at Freya Castle with its Left MASTCam-Z camera. A closer study of the rock’s mineralogy and chemistry using its onboard spectrometer could reveal far more information about Freya Castle’s origins. Planetary scientists raised questions about whether the Perseverance team might send the rover back to do a mineralogical study. For now, however, the MASTcam imagery has prompted much speculation.

“If the rock turns out to be metamorphic and from the lower crust of Mars, it might be a very rare opportunity to examine a rock from an extremely ancient period–perhaps a former sedimentary rock that formed when Mars was extremely young, formed as the Martian crust was just developing,” said Kargel. “It might possibly bear evidence of the oldest hydrosphere known on Mars, or anywhere in the Solar System.”

How Did It Get There?

Regardless of its makeup, planetary scientists now need to determine how this unusual rock got to Jezero Crater in the first place. Since the region has been inundated at least twice in Mars’s long history, the most likely interpretation is that it formed elsewhere and was likely blasted out from below the surface during an impact. Then, it got carried along by water. There’s evidence in the Perseverance image of slight rounding of the protruding edges to support the idea of fluid transport. Materials in a flood can get eroded as they tumbled and bounced along in the water. One scientist at PSI suggested that the rounding shows the rock got carried across at least a few kilometers.

At least one “outlier” suggestion is that maybe the rock has an Earth origin. An ancient impact on our planet could have sent Freya Castle out to Mars, where it landed as an Earth meteorite. That’s not a likely origin, however, since the dynamics of getting Earth meteorites out from Earth to Mars are complex.

Freya Castle’s existence at Jezero Crater points out the historical forces that shaped the planet. In particular, it’s a clue toward understanding the complex sequence of events that brought this rock to its current resting place in Jezero Crater. It takes time to analyze those events and the rock itself, which is likely what the Perseverance team is doing as the mission itself continues its trek across the Martian landscape.

Note: Special thanks to researchers at the Planetary Science Institute for discussing specific aspects of metamorphic rock formation with the author.

For More Information

A Striped Surprise
What are Metamorphic Rocks

The post Perseverance Finds a Strange Black-and-White Striped Rock on Mars appeared first on Universe Today.

The general consensus is that Theia crashed into Earth billions of years ago and led to the formation of the Moon. The story doesn’t end there though since there are a few lines of evidence to suggest the Moon could have been captured by the gravitational pull of the Earth instead. The orbit of the Moon is one such observation that leads to a different conclusion for it’s in-line with the plane of the ecliptic rather than the Earth’s equator. A team of researchers have suggested capture theory was the Moon’s origin. 

The Giant Impact Theory is by far the most widely accepted theory to explain the origin of the Moon. In the theory, Theia is thought to have crashed into the Earth 4.5 billion years ago. Following the catastrophic impact, debris from Earth and Theia was ejected out into space and, over time the material is thought to have coalesced to form the Moon. There is a lot of evidence to suggest this, such as the lunar composition which is very similar to the mantle of Earth. 

This image shows what the collision between Earth and Theia might have looked like. Image: Hagai Perets

The data collected from lunar soil samples from over 6 Apollo missions revealed calcium rich, basaltic rocks. The composition was identified by chemical and isotopic analysis and was dated at 60 million years after the formation of the Solar System. Using this information, planetary scientists concluded that, due to the similar with the Earth’s mantle, the Moon must have formed from the collision. That was back in 1984. 

A new piece of research published in the Planetary Science Journal by Darren Williams from Penn State Behrend in Pennsylvania and Michael Zugger from the Applied Research Lab at Penn State proposes an alternative. They suggest that instead, the moon was captured during a close encounter between a young Earth and a terrestrial binary — the moon and another rocky object.

This is not a unique idea though since it has been seen to happen elsewhere in the Solar System. Williams points out that Triton, the largest moon of Neptune may have experienced a similar origin. Triton is thought to have been a Kuiper Belt object that got pulled into an orbit by Neptune. Of the Kuiper Belt objects, 1 in every 10 are thought to be binary objects supporting the theory that the Moon’s formation could well have involved a binary pair. The orbit of Triton around Neptune is retrograde, meaning it moves opposite to the direction of the rotation of the planet. It’s also tilted by 67 degrees to the equator of Neptune. 

Global color mosaic of Neptune’s largest moon, Triton, taken by NASA’s Voyager 2 in 1989. (Credit: NASA/JPL-Caltech/USGS)

The team argue that, even though Earth could have captured an object larger than the Moon, the orbit is unlikely to have been stable. In the capture scenario, the original lunar orbit would have started as an ellipse but, through the effects of tides, been altered. By calculating the tidal changes, the team identify that initial lunar orbit would have contracted over thousands of years, becoming more circular at the same time. It’s this orbit that we see today. 

Now we see the tidal forces causing the Moon to slowly drift away from Earth at a rate of 3cm per year. The team’s calculations showed mathematically that a binary exchange captured satellite may well have led to the behaviour shown by the Earth-Moon system. If this was the case, it doesn’t explain how the Moon formed, just how it came to be a part of our planetary system. 

Source : What is the moon’s true origin story?

The post Was the Moon Captured? appeared first on Universe Today.

Despite decades of large-scale optical surveys, there are still mysteries about the Milky Way galaxy that astronomers are eager to resolve. This is particularly true of its internal structure and the core region, which is difficult to survey due to clouds of gas and dust in the interstellar medium (ISM). This material absorbs visible light, making fainter objects difficult to see in optical wavelengths. Luckily, advances in infrared astronomy have enabled surveys of the Milky Way that have revealed things that would otherwise remain invisible to us.

For more than 13 years, an international team of astronomers has been observing the Milky Way using the ESO’s 4.1-meter Visible and Infrared Survey Telescope for Astronomy (VISTA). In a recently published study, they announced the release of their final data product: a gigantic infrared map of the Milky Way containing more than 1.5 billion objects—the most detailed map our galaxy has ever created! With over 200,000 images and 500 terabytes of data, this map is also the largest observational project ever carried out with an ESO telescope.

Located at the European Southern Observatory’s (ESO) Paranal Observatory in Chile, the VISTA telescope is responsible for mapping large areas of the sky. This latest map contains data gathered by the VISTA Variables in the Via Lactea (VVV) survey and its companion project, the VVV eXtended (VVVX) survey. Led by Dante Minniti, an astrophysicist at Universidad Andrés Bello in Chile, these surveys used the VISTA InfraRed CAMera (VIRCAM) to survey the Milky Way, the Small and Large Magellanic Clouds (SMC, LMC), and extragalactic space.

This spectacular view of the VISTA telescope was taken from the roof of the building during the opening of the enclosure at sunset. The VLT is visible on the neighboring mountain. Credit: VVV Survey/ESO

This latest map contains about ten times as many objects as the previous version, which the VVV Survey team released in 2012. As always, the ability to see the Universe in the infrared wavelength allows astronomers to see objects that would otherwise be obscured by clouds of gas and dust. These include newborn stars embedded in dusty globular clusters, brown dwarfs, and free-floating planets (FFP)—aka rogue planets—that do not orbit stars. “We made so many discoveries, we have changed the view of our Galaxy forever,” said Minniti in a recent ESO press release.

The observations began in 2010, using the camera’s 16 special detectors with a combined resolution of 67 million pixels to survey billions of point sources of light in an area measuring 520 deg2. By observing each patch of sky many times, the team could determine the locations and proper motions of the 1.5 billion objects and monitor them for changes in brightness. The team also tracked hypervelocity stars kicked out of our galaxy’s central region due to gravitational interaction with the supermassive black hole (SMBH) there – Sagittarius A*.

The observations lasted for 420 nights, ending in the first half of 2023. The resulting map provides an accurate 3D view of the Milky Way’s inner regions that were previously obscured by dust. With the surveys now complete, the ESO’s Paranal Observatory is preparing for future surveys by upgrading the VISTA with the 4-meter Multi-Object Spectrograph Telescope (4MOST) instrument. This new instrument will allow VISTA to perform large spectroscopic surveys, capturing the spectra of 2400 objects simultaneously over an area of the sky equivalent to 20 full Moons.

Meanwhile, the Very Large Telescope (VLT) will receive the new Multi-Object Optical and Near-infrared Spectrograph (MOONS) instrument. MOONS consists of two identical cryogenic spectrographs (with 500 fibers each), allowing astronomers to obtain optical and near-infrared spectra for about 1000 objects simultaneously. The combined power of these instruments will provide spectra for millions of the objects surveyed by VVV and VVX, and many more discoveries are anticipated!

Further Reading: ESO, Astronomy & Astrophysics

The post The ESO Releases the Most Detailed Infrared Map of our Galaxy Ever Made appeared first on Universe Today.

You might remember the story of the two astronauts on board the International Space Station that went for an 8 day mission, that was back in June 2024! Butch Wilmore and Suni Williams have been stranded there ever since but their ride home has just arrived at the ISS. A SpaceX Crew Dragon capsule carrying Nick Hague and Aleksandr Gorbunov has just docked so that the two can join the Expedition 72 crew already on board. There are now 11 people on boar the ISS but the Crew-9 capsule will return in February carrying Wilmore and Williams finally back home. 

Being stranded in space sounds like the stuff of nightmares but the reality is a little more mundane….if space travel can ever be classed as mundane! The two astronauts living this reality, Wilmore and Williams have been stuck on board the ISS as a result of thruster problems on the trouble stricken Starliner capsule. Tests were completed, analysis undertaken but the module was autonomously returned home for further tests without the risk to an onboard crew. 

International Space Station. Credit: NASA

Enter the Dragon capsule. Developed by SpaceX, the state of the art spacecraft was designed to ferry astronauts to and from the ISS. It’s been a key part of NASA’s Commercial Crew Program and has been a significant development in the private space sector. One of the key features of the capsule is in its automation, not requiring any pilot to complete its journey but it, if needed, be controlled manually. Somewhat more reliably than the Starliner, the Dragon capsule safely docked and its hatch opened at 7.04pm EDT (23:04 GMT.) 

The Dragon capsule is launched into low Earth orbit by the Falcon 9 rocket. The two stage rocket was also developed by Space X and has operated reliably since its first launch in June 2010. Together with the Dragon capsule, they can deliver crewed and uncrewed missions into low Earth orbit. 

A SpaceX Falcon 9 rocket carrying the company’s Crew Dragon spacecraft is launched from Launch Complex 39A on NASA’s SpaceX Demo-2 mission to the International Space Station with NASA astronauts Robert Behnken and Douglas Hurley onboard, Saturday, May 30, 2020, at NASA’s Kennedy Space Center in Florida. The Demo-2 mission is the first launch with astronauts of the SpaceX Crew Dragon spacecraft and Falcon 9 rocket to the International Space Station as part of the agency’s Commercial Crew Program. The test flight serves as an end-to-end demonstration of SpaceX’s crew transportation system. Behnken and Hurley launched at 3:22 p.m. EDT on Saturday, May 30, from Launch Complex 39A at the Kennedy Space Center. A new era of human spaceflight is set to begin as American astronauts once again launch on an American rocket from American soil to low-Earth orbit for the first time since the conclusion of the Space Shuttle Program in 2011. Photo Credit: (NASA/Joel Kowsky)

The occupants of the Dragon, Nick Hague and cosmonaut Aleksandr Gorbunov joined the 9 existing crew members of the Expedition 72 crew. The astronauts on board are Matthew Dominick, Michael Barratt, Jeanette Epps, Don Petitt, Butch Wilmore, Suni Williams and cosmonauts Alexander Grebenkin, Alexey Ovchinin and Ivan Vagner.

Assuming all goes to plan, Wilmore and Williams will return back with the Dragon capsule in February turning their 8 day mission to an 8 month mission! Fingers crossed for them. 

Source : Expedition 72 Welcomes Crew-9 Duo Aboard Station

The post Stranded Astronauts To Get Their Ride Home appeared first on Universe Today.

To help speed decarbonization, state regulators should reconceive of gas and electric utilities as serving the same purpose, according to a new report. Without coordinated action, the energy transition could become slower, more expensive, and more inequitable, the authors warn.

Researchers have made a discovery that changes what we know about light and materials. They found that engineered achiral (symmetric) materials, called achiral plasmonic metasurfaces, can absorb light differently depending on the handedness of the wavefront of light. This was surprising because, for years, such materials were found to be indifferent to any optical probes and does not show such selective absorption.

Palladium, a rare metallic element, can rapidly generate water from hydrogen and oxygen. Researchers witnessed this process at the nanoscale for the first time with an electron microscope. By viewing the process with extreme precision, researchers discovered how to optimize it to generate water at a faster rate. Process could be used to generate water on-demand in arid environments, including on other planets.

Engineers developed a system that helps robots quickly map a scene and identify items they need to complete a set of tasks.

Engineers developed a system that helps robots quickly map a scene and identify items they need to complete a set of tasks.

Data from an international space mission is confirming decades worth of speculation about the galactic neighborhoods of supermassive black holes.

Hyperspectral imaging is a useful technique for analyzing the chemical composition of food and agricultural products. However, it is a costly and complicated procedure, which limits its practical application. A team of researchers has developed a method to reconstruct hyperspectral images from standard RGB images using deep machine learning.

Google, Microsoft and others have taken big steps towards error-free devices, hinting that quantum computers that solve real problems aren’t far away

Plankton that lived during the last glacial maximum have helped confirm the accuracy of our climate models – suggesting the predictions those models make about future El Niño events are accurate too

Plankton that lived during the last glacial maximum have helped confirm the accuracy of our climate models – suggesting the predictions those models make about future El Niño events are accurate too

Coral reefs around the world are at risk of collapse due to rising temperatures and acidifying oceans, but the natural adaptability of some species may help buy time