It’s great to see so many private organisations entering the space sector. Space Perspective are another and they have just completed a successful uncrewed capsule ascent to an altitude of 30km. Their Neptune-Excelsior capsule was carried by a balloon and landed in the ocean 6 hours later. It was able to maintain its cabin pressure and stability throughout the flight proving that it met the requirements for future passenger flights starting in 2025.  Space Perspective was founded in 2019 by Jane Poynter and Taber MacCallum. Their focus in the sector is space tourism and they aim to provide an accessible way for people to experience space without the need for rockets. The concept is to provide trips on board their pressurised capsules which are lifted gently to the upper atmosphere by large hydrogen filled balloons. The gentle journey is a far cry from the adrenalin fuelled rocket launches we are accustomed to seeing but still allows passengers to take in the view of the Earth from an altitude of 100,000 feet (30km.) The experience should be a comfortable and luxurious one with large windows, spacious interior and a smooth, calm experience.  A view of Earth’s atmosphere from space. Credit: NASA The concept is a fabulous one allowing access to space by anyone and especially those less inclined to attach themselves to a controlled explosion. It’s a carbon-neutral spaceflight experience and this latest test of the Neptune-Excelsior capsule is a positive step forward. The ascent began at the Marine Spaceport from the deck of MS Voyager off the coast of St Petersburg in Florida on 15 September 2024.  Apollo 11 launch using the Saturn V rocket The whole journey lasted 6 hours, and reaching an altitude of 100,000 feet took the capsule above 99% of the Earth’s atmosphere. Enroute the Neptune-Excelsior travelled high above the ocean and on completion of the ascent the module completed a controlled descent and completed a splashdown landing. The flight marks a significant milestone in space tourism opening up a space experience to all and bringing with it innovations in spaceport technology, spacecraft design and flight safety.  Enabling the flight are a number of technological advances; launch and ascent systems, environment management and thermal management. The launch system employed a new four-roller system to raise the balloon and get it airborne. It’s an approach that significantly reduces the cost of launch to high altitude, reduces the risk and the carbon footprint.  Unlike other capsules designed for space, the Neptune module has been designed for comfort and enjoyment with the largest windows ever flown.  The Development Test Flight has enabled the collection of data to inform the next phase in the programme. Teams of engineers will analyse the results and the capsule to see how the pressurisation, structure and thermal systems have handled the flight setting the stage for the first crewed flight.  Is this for everyone? Space Perspective have sold at least 1,800 tickets at a cost of $125,000 that’s compared to more conventional rocket based journeys costing anything from $250,000 and above. Alas for now, the price point still puts space travel outside the financial capability of most but it’s a great step toward driving down the cost and opening up the amazing wonders of space to everyone.  Source : Space Perspective Successfully Completes Development Flight 2 The post Space Perspective Completes a Test Flight, Sending a Balloon to 30 km appeared first on Universe Today.

The Milky Way is special because it is our home. No matter where we are on Earth we can see its arc of light overhead if the night is dark enough. But how similar is our galaxy to others? Is it an unusual spiral galaxy, or is it rather typical in the cosmos? Before we had discovered exoplanets, astronomers generally thought our solar system was rather typical. Sure, there would be differences, but the general arrangement of rocky worlds close to the Sun and cold gas giants in the outer system made sense. However when we studied planetary systems we found ours was rather unusual. Most planets orbit red dwarfs, not sun-like stars, and large gas giants often orbit close to their star. Now that we have sky surveys of galaxies throughout the Universe, we can answer the same question of the Milky way, as a recent study shows. The study is based on the Satellites Around Galactic Analogs (SAGA) Survey, which began collecting data in 2013. The goal of SAGA is to look at the small galaxies which orbit large galaxies. The team looked at 101 galaxies with masses similar to the Milky Way and found 378 satellite galaxies for them. Because of observational limits, this only covers satellites with a mass of about a million Suns or more. In this range our galaxy has four satellites. We know of many more, but most of them are below the mass cutoff. This would seem to indicate that the Milky Way is rather typical. But then the team looked at those galaxies with a large companion, like the Large Magellanic Cloud we see in the southern hemisphere. For those galaxies the number of satellites is typically much larger than four. The Milky Way has an unusually low number of satellites. One reason for this may be that the Large Magellanic Cloud entered our sphere of influence rather recently on the cosmic timeline. A second study based on the SAGA data looked at star formation in the satellite galaxies. It found that the closer a satellite is to the main galaxy the more likely it is to still be producing stars. This is similar to what we see among the Milky Way satellites. So it seems that while the Milky Way is a little unusual, it isn’t unique among galaxies of similar mass. But it will always be our special spiral galaxy. Reference: Mao, Yao-Yuan, et al. “The SAGA Survey. III. A Census of 101 Satellite Systems around Milky Way-mass Galaxies.” arXiv preprint arXiv:2404.14498 (2024). Reference: Geha, Marla, et al. “The SAGA Survey. IV. The Star Formation Properties of 101 Satellite Systems around Milky Way-mass Galaxies.” arXiv preprint arXiv:2404.14499 (2024). The post How Does the Milky Way Compare to Other Galaxies? appeared first on Universe Today.

I don’t think it’s something I have ever really thought of! Robotic explorers can travel around the Solar System visiting our neighbouring planets but when they arrive, sometimes a scientific package must be deployed to the surface. Never occurred to me just how that’s achieved! With a number of landers scheduled to visit the Moon, NASA are testing a new robotic arm called the Lightweight Surface Manipulation System AutoNomy capabilities Development for Surface Operations or LANDO for short! It will lift payloads off the lander and pop them down gently on the surface of the Moon.  The Moon has always held a special place in our hearts. Since the first humans saw it as they gazed up at the sky, their descendents continued the fascination with our nearest neighbour. Artists, musicians, poets and writers are among just a few of the members of our society that have reflected on its beauty. It was only natural that it would be the first target for human exploration at the dawn of space flight. The Apollo missions saw the first human visitors to the Moon and now we wait with bated breath as Artemis looks set to take us back again very soon.  Aldrin on the Moon. Astronaut Buzz Aldrin walks on the surface of the moon near the leg of the lunar module Eagle during the Apollo 11 mission. Mission commander Neil Armstrong took this photograph with a 70mm lunar surface camera. While astronauts Armstrong and Aldrin explored the Sea of Tranquility region of the moon, astronaut Michael Collins remained with the command and service modules in lunar orbit. Image Credit: NASA Even with human explorers it’s likely only to be a few at a time so mission planners are turning to robotic helpers for the more mundane work. A team of researchers at the Langley Research Centre in Virginia have been working upon a piece of robotic hardware with new software that can operate autonomously to move objects around on the surface! The team, led by Dr Julia Cline from NASA demonstrated the LANDO system and it performed perfectly. Looking like a movie set, the team established the arena to look like the Moon, complete with boulders that Hollywood would be proud of. The team undertook their first demo by lifting a payload off a tall black pedestal and onto the floor. They then upped the challenge and tried the same manouver but with a small rover instead. Both tests were succesful. Closeup of lunar surface (Credit NASA) Pivotal to the system is a series of sensors on the camera and encoders affixed to the side of the package. Once the system was ready the camera scanned the area looking for the payload which was outlined with the encoders (somewhat like a QR code.) Once it identified the item the robotic arm gently swung over the object and carefully manoeuvred its hook to snare the package. With a destination already defined using a graphical interface of the scene, the robotic arm moved around and dropped the placed the package just where the team commanded it too.  After a succesful delivery the hook slowly disengaged, returned to its home position and paused, ready for the next command. The testing nicely demonstrated the reliability of the system setting the scene for further more advanced tests. Now the team are looking to develop a larger more robust version that can be tested ahead of its first lunar mission. The use of robotic arms like LANDO are of immense benefit, helping us to explore the Moon. Not only will they help with repetitive tasks but they can perform more precise scientific studies even in the relatively hostile environment of the lunar surface. Their high levels of dexterity and reliability mean they are an ideal tool for further development with lunar ready versions already being worked upon. Source : Robotic Moving ‘Crew’ Preps for Work on Moon The post Unloading Cargo on the Moon appeared first on Universe Today.

Before you read the rest of this article know there are no known threats to life on Earth! We shouldn’t sit complacently on this tiny rock in space though so NASA have been working on ways to neutralise potential asteroid threats should they arise. The DART mission proved it was possible to alter the trajectory of an asteroid in space. Direct impact though where a probe smashes into the rock is one way but potentially not the best. A team of researchers have now been exploring ways that a nuclear explosion near an asteroid may send a blast of X-rays sufficiently powerful to vaporise material generating thrust to redirect the asteroid.  Statistically the risks of an asteroid are low but the ‘impact’ of such an event could be catastrophic. The majority of asteroids that enter our atmosphere burn up giving us the stunning sight of a ‘shooting star’  but those over 1km wide could cause widespread damage and devastation. The likelihood is rare and might occur once every several hundred thousand years but smaller objects hit more often. They can also create significant localised damage. Take the Chelyabinsk event in Russia in 2013 when an asteroid exploded in mid air sending shockwaves across hundreds of kilometres.  This image of a vapor trail was captured about 125 miles (200 kilometers) from the Chelyabinsk meteor event, about one minute after the house-sized asteroid entered Earth’s atmosphere. Credits: Alex Alishevskikh Whilst the risk is low we must put in place a plan to deal with such threats when they arise. The Double Asteroid Redirection Test mission that NASA launched back in 2021 sent a probe to the binary asteroid system Didymos with its tiny moon Dimorphos. The probe hit Dimorphos in September 2022 and very slightly altered the orbit proving it is possible to effect change in an asteroid trajectory. Whilst the approach worked, the scope of such an approach is limited since colliding a spacecraft may not be so effective on large asteroids. Coupled with the liklihood of not getting much notice and an alternative, more, effective approach is needed.  The asteroid Dimorphos was captured by NASA’s DART mission just two seconds before the spacecraft struck its surface on Sept. 26, 2022. Observations of the asteroid before and after impact suggest it is a loosely packed “rubble pile” object. Credit: NASA/JHUAPL Other approaches have been explored from deployment of fusion engines to the target rock, focussing laser beams on them, neutron bursts and of course nuclear blasts that generate X-ray radiation. Analysis of these options reveals that only the latter, nuclear blasts has been deemed as a suitable approach for the neutralisation of the threat of a large asteroid impact when only limited time is available.  A team of researchers led by Nathan W Moore has shown through simulations that a nuclear bomb could indeed deflect an incoming asteroid. Much of the energy release from a nuclear explosion is in the form of X-rays. the team showed that the X-ray emission would be sufficiently powerful to be able to vaporise the surface of an asteroid causing the results vapour to slowly propel the asteroid in the opposite direction. You can think of this as a very basic rocket engine with the vapour producing thrust. In simulations, the test asteroid reached speeds of 250 kilometres per hour!  The results showed for the first time that X-rays could work and may provide sufficient protection against an incoming asteroid up to 4 km wide assuming of course, we have sufficient notice! There in lies the challenge, asteroids are typically dark and finding them against the blackness of space can be a challenge. The more time we have, then the greater chance we have of deflection being a viable proposition.  The next step is for actual tests however, nuclear explosions come with high costs, high risks and a whole bunch of international legal restrictions. Careful planning is now needed with perhaps a little more research before this approach can be put on the shelf to be used should the need arise!  Source : Simulation of asteroid deflection with a megajoule-class X-ray pulse The post Nuclear Detonations Could Deflect Dangerous Asteroids Away from Earth appeared first on Universe Today.

A remote annular solar eclipse bookends the final eclipse season for 2024. The final eclipse of the year is almost upon us. If skies are clear, a few lucky observers and intrepid eclipse-chasers will get to witness the passage of the Moon in front of the Sun one last time on Wednesday, October 2nd during an annular solar eclipse. The eclipse is the final one of the current season, and the last solar eclipse for 2024. The first—the April 8th total solar eclipse spanning North America—was witnessed by millions. This week’s eclipse is by contrast much more bashful. The path and timing for Wednesday’s annular solar eclipse. Credit: from Michael Zeiler’s Atlas of Solar Eclipses (2020 to 2045). Why Do Annulars Occur? An annular solar eclipse occurs when the Moon is visually too small to cover the Sun. Both vary in apparent size throughout the month and year, as the orbits of the Moon and the Earth are both elliptical. The shadow of the Moon falls short of the surface of the Earth during an annular eclipse, and the ‘ring of fire’ path is known as an antumbra. Stages of the 2019 annular eclipse as seen from Guam. Credit: Eliot Herman We often marvel at how ‘perfect’ total solar eclipses are, but this situation slowly changing. Going forward, annulars are already more common, as the Moon slowly moves away from the Earth… in about 600 million years annulars will win this battle for good, as total solar eclipses will cease to occur on the surface of the Earth. The path for Wednesday’s annular solar eclipse over the southern tip of South America. Credit: from Michael Zeiler’s Atlas of Solar Eclipses (2020 to 2045). There’s good reason why this eclipse is annular. The Moon reaches its most distant apogee of 2024 on October 2nd at 50 minutes after eclipse conjunction at 19:08 Universal Time, at 406,516 kilometers from Earth. Eclipse Path and Circumstances The path crosses the South Pacific, and only makes landfall across Easter Island, Chile, Argentina. Maximum annularity reaches 7 minutes and 25 seconds in duration northwest of Easter Island. There’s a chance for some excellent ‘horns of the Sun’ shots towards sunset around to Falkland Islands and the Horn of South America. An animation of Wednesday’s eclipse. Credit: NASA/GSFC/A.T. Sinclair The partial phases of the eclipse will be visible from Antarctica and northern New Zealand, across southern South America all the way up to Brazil, Paraguay and Peru, up to a small sliver of the west Pacific coast of Mexico. The Falkland Islands in the Atlantic ocean will see a narrow miss, with Stanley seeing an 84% obscured partial eclipse. This eclipse also marks the end of the second and final eclipse season for 2024. This season was book-ended by the slight partial lunar eclipse earlier this month. This eclipse is also member 17 in the 70 eclipses in relatively new Solar Saros Series 144. This saros is a prolific producer of annulars, and started on April 11th, 1736 and will end on May 5th 2980. Viewing and Safety Unlike a total solar eclipse, proper safety precautions must be taken during Wednesday’s eclipse… even during the annular phase. A few percent of the Sun is still pretty bright, enough to give the sky a deep blue-steely tint, the only hint that something might be afoot. NASA has a pretty solid eclipse safety page. There’s another low tech way to observe the eclipse. Keep an eye out for tiny crescent suns cast though natural pin hole projectors. These can include gaps in tree leaves and latticework. Kitchen utensils such as graters and strainers will also do the trick. Crescents cast through gaps in the tree leaves seen from Mapleton Maine during the June 2021 annular solar eclipse. Credit: Dave Dickinson. Comet T-ATLAS ‘may’ also make an appearance during the eclipse. Have any comets ever appeared during an annular? Certainly bright comets have made themselves known during the daytime. There’s now a chance that Comet Tsuchinshan-ATLAS ‘may’ reach negative magnitudes in early October, and the comet will be ~20 degrees from the Sun during next Wednesday’s annular eclipse… To be sure, it’s an extremely remote chance to see comet T-ATLAS against a bright sky, but I remember noticing Venus becoming plainly visible on April 8th about 10 minutes prior to totality, so you just never know… The next eclipses in 2025 includes only two partial solars worldwide: one on March 29th for the North Atlantic, and another on September 21st for New Zealand and the South Pacific. The next annular won’t occur until February 17th, 2026 for the remote Antarctic. Will the eclipse be carried live? As of writing this, no live streams along the path have emerged, but we’ll drop them here if any turn up. if you have the chance, don’t miss this final eclipse of the year. The post An October Annular Solar Eclipse Rounds Out 2024 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.

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.

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.

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

Why is it important to search for exoplanets in triple star systems and how many can we find there? This is what a recent study accepted by Astrophysics & Space Science hopes to address as a pair of researchers from the University of Texas at Arlington investigated the statistical likelihood of triple star systems hosting exoplanets. This study holds the potential to help researchers better understand the formation and evolution of triple star systems and whether they are suitable to find life as we know it. Here, Universe Today discusses this incredible research with Dr. Manfred Cuntz, who is a physics professor at the University of Texas at Arlington and lead author of the study, regarding the motivation behind the study, the most significant results, the importance of studying triple star systems, and the likelihood of finding exolife in triple star systems. Therefore, what was the motivation behind the study? Dr. Cuntz tells Universe Today, “Ages and metallicity (i.e., the amount of heavy elements = elements other than hydrogen and helium) are fundamental properties of stars – a statement that applies to all stars. Considering that most stars (which however does not apply to the sun) are members of higher order systems – the study of stars in triple stellar systems is a natural extension of research focusing on single stars.” For the study, the researchers conducted a statistical analysis regarding both the ages and metallicities of triple star systems with a total of 27 confirmed exoplanets based on past research, with the number of exoplanets in each system ranging from 1 to 5. The ages of the triple star system ages, with margins of error, ranged between 20 million years old to 7.2 billion years old. For context, our Sun is estimated to be slightly more than 4.6 billion years old. The metallicities of the star systems, with margins of error, ranged between -0.59 to +0.56, which is often calculated based on the ratio of iron to hydrogen (Fe/H), and is also calculated with the equation X + Y + Z =1, with X being the fraction of hydrogen, Y being the fraction of helium, and Z being everything else (i.e., carbon, oxygen, silicon, iron, etc.). These values range between -4.5 to +1.0, with stars exhibiting 0, -1, greater than 0, and less than 0 indicating a star is equal in iron abundance to our Sun, one-tenth the iron abundance of our Sun, greater metal content than our Sun, and less metal content than our Sun, respectively. Therefore, what were the most significant results from this study? “Two highly significant results have been identified,” Dr. Cuntz tells Universe Today. “First, stars in triple stellar systems are on average notably younger than stars situated in the solar neighborhood. The most plausible explanation is a possible double selection effect due to the relatively high mass of planet-hosting stars of those systems (which spend less time on the main-sequence than low-mass stars) and that planets in triple stellar systems may be long-term orbitally unstable. The stellar metallicities of those stars are on average solar-like; however, owing to the limited number of data, this result is not inconsistent with the previous finding that stars with planets tend to be metal-rich as the deduced metallicity distribution is relatively broad.” The distances to the respective triple star systems range between 4.3 to 1,870 light-years from Earth, but only 6 of the 27 triple star systems reside within 100 light-years away. These six triple star systems include Alpha Centauri (4.3 light-years), Epsilon Indi (11.9 light-years), LTT 1445 (22.4 light-years), Gliese 667 (23.6 light-years), 94 Ceti (73.6 light-years), and Psi1 Draconis (74.5 light-years), with the number of total exoplanets (with exoplanet candidates) within each system being 3 (2), 1, 1, 2 (1), 1, and 1, respectively. For context, as of September 2024, the total number of confirmed exoplanetary systems within our cosmos is more than 4,300 that encompasses almost 5,800 exoplanets. But despite the small number of triple star systems that host exoplanets, what is the importance of studying triple star systems? Dr. Cuntz tells Universe Today, “Most stars (which however does not apply to the sun) are members of higher order systems, especially binaries – and in less common cases triple stellar systems, and systems of even higher order. Therefore, the study of planets hosted by triple stellar systems is a natural extension of the standard approach focusing on planets around single stars. The current study focuses on some of the properties of stars in triple stellar systems, which are also known to host (a) planet(s) – a relatively rare setting. The importance of the current study is to expand our general understanding of star-planet systems.” For Alpha Centauri, the exoplanet, Proxima Centauri b, has been confirmed to be terrestrial (rocky), approximately the size of Earth in both radius and mass, and orbits within the habitable zone (HZ) of Proxima Centauri, one of the stars that comprise the Alpha Centauri triple star system. The only other terrestrial exoplanet orbiting within its star’s HZ is Gliese 667 Cc, whose mass and radius is larger than the Earth, designating it as a super-Earth. Therefore, given the small number of triple star systems that have exoplanets and even fewer that host terrestrial exoplanets orbiting in its HZ, what is the likelihood of finding exolife in triple star systems? “The only planet where we know for sure that life does exist is Earth,” Dr. Cuntz tells Universe Today. “However, through both observational and theoretical studies during many decades of committed work, scientists are convinced that exolife is almost certainly real. This statement should also apply to planets in triple star systems. However, those planets are typically subject to relatively variable environmental forcings (e.g., variable amounts of radiation received by the stellar components), which is expected to reduce the likelihood of advanced life forms, but should still permit microbial life, especially extremophiles.” As the number of confirmed exoplanets continues to grow, so should the confirmed number of triple star systems that host exoplanets, as well. When science fiction fans read about multi-star systems, they almost immediately think of the iconic scene in Star Wars: A New Hope of Luke Skywalker watching two stars setting on the horizon. While Tatooine was habitable for humans and other interesting life forms, this might not be the case in the real world, as demonstrated by Proxima Centauri b currently being the only Earth-like exoplanet orbiting in its HZ within 100 light-years from Earth. Therefore, what constraints should scientists put on finding life in triple star systems? Should we instead study their moons, as the film Avatar depicted the semi-habitable moon, Pandora, orbiting a much larger exoplanet within the Alpha Centauri system? Are triple star systems with exoplanets as rare as the statistics show today? “The search for life outside of planet Earth continues to be a fascinating topic,” Dr. Cuntz tells Universe Today. “Political and societal support for ongoing and future space missions is highly appreciated. We, as scientists, are grateful about the ongoing support by the taxpayers around the world, but especially here in the U.S.” What new discoveries about triple star systems will researchers make in the coming years and decades? Only time will tell, and this is why we science! As always, keep doing science & keep looking up! Reference: Cuntz, Manfred & Patel, Shaan D. “On the Age and Metallicity of Planet-hosting Triple Star Systems.” Astrophysics and Space Science (2024) (accepted) The post We Don’t See Many Planets in Old Triple Star Systems appeared first on Universe Today.