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Combining two neural networks has helped researchers predict potentially disastrous collapses in complex systems, such as financial crashes or power blackouts

Rehabilitation robots, first introduced in the 1990s, are just what they sound like – robotics used to aid in regaining function through rehabilitation following an injury. The idea sounds compelling, and the technology has been advancing steadily. But still we have to ask ourselves the question – do they actually help, and what is the evidence? A recent comprehensive meta-analysis and systematic […]

The post The Evidence for Rehabilitation Robots first appeared on Science-Based Medicine.

An orange layer on the tips of Komodo dragons’ teeth may give the enamel extra strength for ripping apart their prey

Researchers are calling for greater protection for basking sharks after a camera on a tagged shark recorded a collision for the first time

In an effort to understand ancient Neanderthal food preparation techniques, researchers butchered five wild birds using flint stone tools and roasted them

People generalize to form beliefs about a large language model's performance based on what they've seen from past interactions. When an LLM is misaligned with a person's beliefs, even an extremely capable model may fail unexpectedly when deployed in a real-world situation.

An international collaboration seeks to innovate the future of how a mechanical man's best friend interacts with its owner, using a combination of AI and edge computing called edge intelligence. The overarching project goal is to make the dog come 'alive' by adapting wearable-based sensing devices that can detect physiological and emotional stimuli inherent to one's personality and traits, such as introversions, or transient states, including pain and comfort levels.

Researchers have successfully made super-heavy element 116 using a beam of titanium-50. That milestone sets the team up to attempt making the heaviest element yet: 120.

Think about background radiation and most people immediately think of the cosmic background radiation and stories of pigeon excrement during its discovery. That’s for another day though. Turns out that the universe has several background radiations, such as infrared and even gravitational wave backgrounds. NASA’s New Horizons is far enough out of the Solar System now that it’s in the perfect place to measure the cosmic optical background (COB). Most of this light comes from the stars in galaxies, but astronomers have always wondered if there are other sources of light filling our night sky. New Horizons has an answer. No!

Ok lets talk pigeon excrement.  Back in 1965 two telecommunication engineers were exploring signal interference at the Bell Laboratory. Penzias and Wilson detected a faint ‘hum’ in all directions and initially put it down to pigeon excrement as they nested in the horn of the radio receiver. Instead, what they had discovered was the cosmic background radiation, the faint glow that permeates the entire universe and is the thermal radiation left over from the Big Bang. Studying it allows us to understand more about the Universe when it was 380,000 years old. 

The full-sky image of the temperature fluctuations (shown as color differences) in the cosmic microwave background, made from nine years of WMAP observations. These are the seeds of galaxies, from a time when the universe was under 400,000 years old. Credit: NASA/WMAP

In the late 80’s a different type of background radiation was detected; the infrared background radiation. It consists of the diffuse infrared glow that fills the universe coming from numerous sources throughout the history of the universe. It is mostly from thermal emissions from dust grains heated by stellar radiation. In addition to this is the gravity wave background although this has yet to be detected. 

Another hotly debated background is the cosmic optical background (COB), a diffuse light which originates from stars and galaxies and spans the whole of the visible spectrum. There has been gathering momentum in its study however with observations from Hubble Space Telescope and the Spitzer Infrared Telescope. The studies however revealed that a large contribution to a general background optical glow come from faint unresolved galaxies. The study of the COB allows us to explore the total energy output of the universe, about galaxy and star formation across the history of the cosmos. 

The detection of the COB is a challenging one however with Earth based instruments or even those in Earth orbit plagued by interference. The zodiacal light for example is the result of sunlight scattered by interplanetary dust, it is dominant in the inner solar system  and makes studies of the COB difficult. The New Horizon probe is ideally positioned out beyond the orbit of Pluto over 8 billion kilometres away from interference. On board New Horizons is the LORRI (Long Range Reconnaissance Imager) camera which was identified as an ideal platform to begin a search. 

The New Horizons instrument payload that is currently doing planetary science, heliospheric measurements, and astrophysical observations. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Using images from the LORRI camera, a team of astronomers led by Marc Postman from the Space Telescope Science Institute attempted to measure the COB over the range 0.4 to 0.9 micrometers. The images were from high galactic latitudes to ensure no diffuse light from the Milky Way or scattered light from bright stars. Isolating the COB contribution to the total sky brightness levels required digitally subtracting the scattered light from bright stars and galaxies and from faint stars within the field that were fainter than that detectable by LORRI. Interestingly, the results showed that, based on the estimated galaxy counts in the sampled regions the COB is the result of light from all the galaxies within our observable region of the universe.

Source : New Synoptic Observations of the Cosmic Optical Background with New Horizons

The post New Horizons Measures the Background Light of the Universe appeared first on Universe Today.

The prospect of actually resolving the event horizon of black holes feels like the stuff of science fiction yet it is a reality. Already the Event Horizon Telescope (EHT) has resolved the horizon of the black holes at the centre of the Milky Way and M87. A team of astronomers are now looking to the next generation of the EHT which will work at multiple frequencies with more telescopes than EHT. A new paper suggests it may even be possible to capture the ring where light goes into orbit around the black hole at the centre of the Milky Way. 

Black holes are strange objects that are the powerhouses of many galactic phenomenon. They have a complex anatomy with a singularity at the centre, a point of infinite density where gravity is so intense that the laws of physics cease to work. Surrounding the singularity is the event horizon, the boundary beyond which, nothing, not even light can escape. Just outside the event horizon is the photon ring and it is here that light is bent into a circular orbit around the singularity. Further out than this is the accretion disk but the focus of the next generation Event Horizon Telescope will be the photon ring. 

The Event Horizon Telescope name is a little misleading for it is not one telescope but a global network of radio telescopes that work together to act as a virtual Earth-sized radio telescope. The technology that makes this happen is known as interferometry where the telescopes are all connected together. The very long baseline of the telescope or put more simply the fact it is virtually VERY big means it has incredible resolution capabilities allowing it to capture the event horizon around Sagittarius A at the centre of the Milky Way and also of the black hole at centre of M87.

The ALMA array in Chile. Once ALMA was added to the Event Horizon Telescope, it increased the EHT’s power by a factor of 10. Image: ALMA (ESO/NAOJ/NRAO), O. Dessibourg

The EHT was launched in 2009 but now attention is turning to the next generation. The addition of ten new dishes and a whole host of new technology will transform EHT. Modern high-speed data transfer protocols will speed up transfer times and the addition of new dishes and technology will mean EHT will be able to observe at 86, 230 and 345 GHz simultaneously. This allows for the utilisation of frequency phase transfer techniques where lower frequency data can be used to supplement higher frequency. Using this will mean integration times of minutes at 345 GHz rather than seconds opening up a whole universe of new observations such as, the photon rings of black holes. 

Studies of the supermassive black hole at the centre of M87 and Sagittarius A suggest a magnetically arrested accretion disk. In this accretion model, the accretion disk forms a series of irregular spiral streams and a vertical magnetic field, which is split into separate field lines, pokes through the accretion plane. As the disk rotates the material spirals inward, dragging the field lines and twist them around the axis of rotation leading to the formation of jets. These magnetically arrested disks exhibit symmetrically polarised synchrotron emissions which were used by a team of astronomers to study the detectability of the photon ring using next generation EHT.

M87 and the jet streaming away from its central supermassive black hole. Credits: NASA, ESA and the Hubble Heritage Team (STScI/AURA); Acknowledgment: P. Cote (Herzberg Institute of Astrophysics) and E. Baltz (Stanford University)

The paper authored by Kaitlyn M. Shavelle and Daniel C. M. Palumbo from the Princeton University and Harvard & Smithsonian (respectively) show through simulations that the planned enhancements to the EHT are likely to enable the detection of photon rings. In the analyses of the enhancements they find that the higher sensitivity of the new EHT will likely be more critical than better processing techniques in the detection of the photon ring.

Source : Prospects for the Detection of the Sgr A* Photon Ring with next-generation Event Horizon Telescope Polarimetry

The post Next Generation Event Horizon Telescope To Unlock Mysteries of Black Holes appeared first on Universe Today.

A prototype device harvests drinking water from the atmosphere, even in arid places.

A method that helped create two atoms of the rare, super-heavy element livermorium may pave the way towards making the hypothetical element 120

Researchers working at the forefront of an emerging photovoltaic (PV) technology are thinking ahead about how to scale, deploy, and design future solar panels to be easily recyclable. Solar panels made of perovskites may eventually play an important role amid global decarbonization efforts to reduce greenhouse gas emissions. As the technology emerges from the testing stages, it is a perfect time to think critically about how best to design the solar panels to minimize their impact on the environment decades from now.

The field of extrasolar planet studies has grown exponentially in the past twenty years. Thanks to missions like Kepler, the Transiting Exoplanet Survey Satellite (TESS), and other dedicated observatories, astronomers have confirmed 5,690 exoplanets in 4,243 star systems. With so many planets and systems available for study, scientists have been forced to reconsider many previously-held notions about planet formation and evolution and what conditions are necessary for life. In the latter case, scientists have been rethinking the concept of the Circumsolar Habitable Zone (CHZ).

By definition, a CHZ is the region around a star where an orbiting planet would be warm enough to maintain liquid water on its surface. As stars evolve with time, their radiance and heat will increase or decrease depending on their mass, altering the boundaries of the CHZ. In a recent study, a team of astronomers from the Italian National Institute of Astrophysics (INAF) considered how the evolution of stars affects their ultraviolet emissions. Since UV light seems important for the emergence of life as we know it, they considered how the evolution of a star’s Ultraviolet Habitable Zone (UHZ) and its CHZ could be intertwined.

The research team was led by Riccardo Spinelli, an INAF researcher from the Palermo Astronomical Observatory. He was joined by astronomers from the National Institute of Nuclear Physics (INFN), the University of Insubria, and the Astronomical Observatory of Brera. Their paper, “The time evolution of the ultraviolet habitable zone,” recently appeared in the Monthly Notices of the Royal Astronomical Society: Letters.

This infographic compares the orbit of the planet around Proxima Centauri (Proxima b) with the same region of the Solar System. Credit: ESO

As Spinelli told Universe Today via email, the UHZ is the annular region around a star where a planet receives enough UV radiation to trigger the formation of RNA precursors but not so much that it destroys biomolecules. “This zone primarily depends on the star’s UV luminosity, which decreases over time,” he said. “As a result, the UV habitable zone is farther from the star during the early stages of the star’s evolution and gradually moves closer to the star as time progresses.”

As astronomers have known for some time, CHZs are also subject to evolution, owing to changes in the star’s luminosity and heat output, which increase or decrease over time depending on the mass of the star. Addressing the interaction of these two habitable zones could shed light on which exoplanets are most likely to be “potentially habitable” for life as we know it. As Spinelli explained:

“We still do not know precisely how life originated on Earth, but we have some clues suggesting that ultraviolet (UV) radiation may have played a crucial role. Experimental studies, such as the one conducted by Paul Rimmer and John Sutherland in 2018, provide significant insights. In their experiment, Rimmer and Sutherland exposed hydrogen cyanide and hydrogen sulfite ions in water to UV light and discovered that this exposure efficiently triggered the formation of RNA precursors.

“Without UV light, the same mixture resulted in an inert compound that could not form the building blocks of life. Furthermore, RNA demonstrates a resistance to damage from UV radiation, indicating that it likely formed in a UV-rich environment. Indeed, UV radiation was one of the most abundant sources of chemical-free energy on the surface of the early Earth, suggesting it might have played a crucial role in the emergence of life.”

For their purposes, Spinelli and his colleagues sought to determine if (and for how long) the CHZ and the UVZ would overlap – thus facilitating the emergence of life. To this end, the team analyzed data from NASA’s Swift Ultraviolet/Optical Telescope (UVOT) to measure the current UV luminosity of stars with exoplanets that reside in the “classical” HZ. They then consulted data from NASA’s Galaxy Evolution Explorer (GALEX), an orbiting space telescope that has been observing galaxies up to 10 billion years away in the UV wavelength.

Illustration of the Trappist-1 system. Credit: NASA/JPL-Caltech

From GALEX, they incorporated how moving groups of young stars evolve in terms of their near-UV luminosity. “To estimate the evolution in time of the ultraviolet habitable zone, we used the results obtained by Richey-Yowell et al. 2023,” said Spinelli. “In this work, the authors derived an average UV luminosity evolution for each type of star. In our work, we reconstructed the evolution of the UV brightness of stars hosting planets in the classical habitable zone by combining the average evolution derived by Richey-Yowell et al. 2023 and the measurements carried out with the Swift Telescope.”

From this, they determined there is an overlap between the evolution of CHZs and UHZs. These results were especially significant for M-type (red dwarf) stars, where many rocky planets have been found orbiting within their CHZs. Previous research, which includes a 2023 paper by Spinelli and many of the same colleagues, has suggested that M-dwarf stars are not currently receiving near-UV radiation to support the prebiotic chemistry necessary for the emergence of life. However, their conclusions in this latest paper contradicted their previous findings. Said Spinelli:

“We assert that, when examining the evolution of NUV luminosity in M-dwarfs, most of these cool stars are indeed capable of emitting an appropriate amount of NUV photons during the first 1–2 billion yr of their lifetimes to trigger the formation of important building blocks of life. Our results suggest that the conditions for the onset of life (according to the specific prebiotic pathway we consider) may be or may have been common in the Galaxy. Indeed, in this work, we demonstrated that an intersection between the classical habitable zone and the ultraviolet habitable zone could exist (or could have existed) around all stars of our sample at different stages of their life, with the exceptions of the coolest M-dwarfs (temperature less than 2800 K, notably Trappist-1 and Teegarden’s star).”

While they may be a bit of a letdown for those hoping to find life on some of TRAPPIST-1s seven rocky planets, it bodes well for other M-type stars hosting rocky planets in their HZs. This includes the closest exoplanet to the Solar System (Proxima b), Ross 128 b, Luyten b, Gliese 667 Cc, and Gliese 180 b, all of which are within 40 light-years of Earth. These findings could have significant implications for exoplanet and astrobiology studies, which have been transitioning from discovery to characterization in recent years.

These fields will benefit from next-generation telescopes like Webb, the Nancy Grace Roman Space Telescope, and ground-based observatories that will enable Direct Imaging studies of exoplanets.

Further Reading: MNRAS

The post The Ultraviolet Habitable Zone Sets a Time Limit on the Formation of Life appeared first on Universe Today.

On May 30th, the Mars Curiosity rover was just minding its own business exploring Gediz Vallis when it ran over a rock. Its wheel cracked the rock and voila! Pure elemental sulfur spilled out. The rover took a picture of the broken rock about a week later, marking the first time sulfur has been found in a pure form on Mars.

After Curiosity’s encounter with the broken rock and its pure sulfur innards, the rover trundled over to another rock, called “Mammoth Lakes” for a little drilling session. Before it left to explore other rocks, the rover managed to cut into that rock and take samples for further study to find out its chemical composition.

It’s not that sulfur isn’t prevalent on Mars. It is, but in different forms. The stuff is highly abundant in the Solar System, so this find isn’t as surprising as you’d think. However, Curiosity finding pure sulfur in the middle of broken rocks is a new experience in Mars exploration. So, of course, that’s raising questions about how it got there and its implications for habitable environments in Mars’s long history.

Curiosity’s Peregrinations

At the moment, the Curiosity rover is making its way through the Gediz Vallis. That’s a flow channel winding its way down a section of Mount Sharp (aka Aeolis Mons). That’s the central peak of Gale Crater. The rover has been heading up since 2014, charting different surface layers as it goes. Each layer was put down during a different era of Mars’s history. They could contain clues to the planet’s habitability in the past.

NASA’s Curiosity Mars rover captured this view of Gediz Vallis channel on March 31. Floods of water and debris piled rocks and sand into mounds within the channel. The rock the rover broke lies in a channel in this region.
 Credit: NASA/JPL-Caltech/MSSS 

Fast-moving liquid water raged over the surface and carved Gediz. The floods carried a lot of rocks and sand and deposited them all along the way. Other piles of flood debris lie around the region, bearing witness to other ancient floods and landslides. “This was not a quiet period on Mars,” said Becky Williams, a scientist with the Planetary Science Institute in Tucson, Arizona, and the deputy principal investigator of the Mast Camera, or Mastcam on Curiosity. “There was an exciting amount of activity here. We’re looking at multiple flows down the channel, including energetic floods and boulder-rich flows.”

Understanding Sulfur’s Presence

The surface materials in Gediz contain high amounts of sulfates. Those are sulfur-bearing salts that appear as water evaporates. They are a chemical clue that water existed in the region. Judging by some parts of the surface, it also appears the water ponded at some times, in addition to the floods that scoured the landscape and then deposited debris.

Now the planetary science team has to explain how a pure form of elemental sulfur got stuck in the middle of rocks, according to project scientist Ashwin Vasavada. “Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” said Vasavada. “It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”

Putting Sulfur in Context

Sulfur, of course, exists on Earth, which helps scientists understand its behavior and the environments where it’s found. The presence of sulfur can be a result of various geological processes. The sulfur “cycle” includes the flow of sulfur from the core to the surface through volcanism. That’s not unusual. Sulfur commonly appears around volcanic vents. Mt Ijen in Indonesia is a good example. It sports extensive elemental sulfur deposits that are mined.

Traditional sulfur mining at Ijen. Candra Firmansyah. CC BU-SA 4.0.

The volcanic moon Io in the Jupiter system features patches of different allotropes of sulfur. They’re also volcanic in origin, spewed out along with widespread lava flows. This moon has more than 400 volcanic features, making it the most volcanically active (and sulfurous) place in the Solar System.

The Jovian moon Io is seen by the New Horizons spacecraft. The mission’s camera caught a view of one of this moon’s volcanos erupting. The region that Curiosity is investigating shows evidence of different kinds of sulfur-bearing minerals. Courtesy: NASA Goddard Space Flight Center Scientific Visualization Studio.

The pure sulfur in the Mars rock most likely came from volcanic processes. They occurred sometime in the past, but that doesn’t answer how the crystals got inside the rock it crushed. Scientists have known for years that Mars was extremely volcanically active in the past. For a long time, they also thought it was dead, or at least dormant. The planet has no plate tectonics like we see on Earth, either. However, the Mars InSight mission found evidence of some seismic activity on the planet in 2021.

In 2023, planetary scientists at the University of Arizona offered up evidence of a giant mantle plume under Elysium Planitia that drove some kinds of activity in the more recent past. Gale Crater lies in this region and could well have experienced related volcanic and seismic activity during the recent geologic past. If so, that could help explain the presence not only of pure sulfur but also the flood-related sulfates deposited on the surface.

For More Information

NASA’s Curiosity Rover Discovers a Surprise in a Martian Rock
Recent Volcanism on Mars Reveals a Planet More Active than Previously Thought
Sulfur on Mars from the Atmosphere to the Core

The post Curiosity Drives Over a Rock, Cracking it Open and Revealing an Amazing Yellow Crystal appeared first on Universe Today.

One of the challenges engineers face when developing technologies for use in space is that of different gravities. Mostly, engineers only have access to test beds that reflect either Earth’s normal gravity or, if they’re fortunate, the microgravity of the ISS. Designing and testing systems for the reduced, but not negligible, gravity on the Moon and Mars is much more difficult. But for some systems, it is essential. One such system is electrolysis, the process by which explorers will make oxygen for astronauts to breathe on a permanent Moon or Mars base, as well as critical ingredients like hydrogen for rocket fuel. To help steer the development of systems that will work in those conditions, a team of researchers led by computational physicist Dr. Paul Burke of the Johns Hopkins University Applied Physics Laboratory decided to turn to a favorite tool of scientists everywhere: models.

Before we explore the model, examining the problem they are trying to solve is helpful. Electrolysis immerses an electrode in a liquid and uses an electrical current and subsequent chemical reaction to split atoms apart. So, for example, if you put an electrode in water, it would separate that water into hydrogen and oxygen.

The problem comes from reduced gravity. As part of electrolysis, bubbles form on the surface of the electrode. On Earth, those bubbles typically detach and float to the surface, as the density difference between them and the remaining liquid forces them to.

Dr. Burke presented alongside other experts at the Space Resources Week Workshop back in March.
Credit – ESRIC YouTube Channel

However, in reduced gravity, the bubbles either take much longer to detach or don’t do so at all. This creates a buffer layer along the electrode’s length that decreases the electrolysis process’s efficiency, sometimes stalling it out entirely. Electrolysis isn’t the only fluidic process that has difficulty operating in reduced gravity environments – many ISS experiments also have trouble. This is partly due to a lack of complete understanding of how liquids operate in these environments – and that in itself is partly driven by a dearth of experimental data. 

Which is where the modeling comes in. Dr. Burke and his colleagues use a technique known as Computational Fluid Dynamics to attempt to mimic the forces the fluids will undergo in a reduced gravity environment while also understanding bubble formation.

Electrolysis on Earth is typically done with water, but why stop there? The team used their CFD to model two other liquids that might be used in electrolyzers – molten salt (MSE) and molten regolith (MRE). Molten salt is used on Earth, but less commonly than regular water, and has successfully produced oxygen. However, molten regolith electrolysis is still somewhat of a novel use case and has yet to be thoroughly tested. MOXIE, the experiment that famously created oxygen on Mars in 2021, used the carbon dioxide in Mars’ atmosphere and a solid-state electrode – neither representative of molten regolith.

Fraser discusses MOXIE electrolysis with Dr. Michael Hect.

Dr. Burke and his team found that, computationally, at least, MRE has the most challenging conditions in reduced gravity. It has also never been tested in any reduced gravity environment, so for now; these simulations are all engineers have to go on with if they are going to design a system.

There were a few key takeaways from the modeling, though. First, engineers should design horizontal electrodes into MRE systems, as the longer a bubble spreads across an electrode (i.e., as it goes “up” it), the longer it takes for that bubble to detach. In a horizontal configuration, the electrode has less surface area to attach to, making it more likely for the bubbles to detach and float to the surface.

Additionally, the amount of time bubbles remain attached to an electrode scales exponentially with decreasing gravity. That means bubbles on the Moon will take longer to detach than those on Mars, which will take longer than those on Earth. Consequently, electrolysis on the Moon will be less efficient than that on Mars, which will again be less efficient than that on Earth, and mission planners will need to account for these discrepancies if they plan on getting something as mission-critical as oxygen from this process. The smoothness of the electrodes also seems to matter, with rougher electrodes more likely to hold onto their bubbles and, therefore, end up less efficient.

SciShow Space explores the world of MRE.
Credit – SciShow Space YouTube Channel

Other engineering solutions can overcome all these challenges, such as a vibratory mechanism on the electrode to shake the bubbles loose. However, it’s a good idea to consider all the additional complications operations in a reduced gravity environment have before launching a mission. That’s why modeling is so important, but humanity will ultimately have to experimentally test these systems, perhaps on the Moon itself, if we plan to utilize its local resources to sustain our presence there.

Learn More:
Burke et al. – Modeling electrolysis in reduced gravity: producing oxygen from in-situ resources at the moon and beyond
UT – NASA Wants to Learn to Live Off the Land on the Moon
UT – What is ISRU, and How Will it Help Human Space Exploration?
UT – A Robotic Chemist Could Whip up the Perfect Batch of Oxygen on Mars

Lead Image:
Graphic showing the difference in bubble accumulation in low and high gravities.
Credit – Burke et al.

The post Producing Oxygen From Rock Is Harder In Lower Gravities appeared first on Universe Today.

It would be tricky to burn away the outer layers of Uranus, but doing so could reveal a possible stash of gems – in this episode of Dead Planets Society, the hosts reveal a relatively simpler technique to rob the ice giant

Efficient solar panels have helped make solar power the cheapest form of energy on the planet, and new designs based on space-age technology are going further

Why July 2024 is a prime time to see distant Pluto before it fades from view.

Lots of the ‘wow factor’ in astronomy revolves around knowing just what you’re seeing. Sure, a quasar might be a faint +14th magnitude point of light seen at the eyepiece, but it’s also a powerful energy source from the ancient Universe, billions of light-years distant.

The same case is true for finding Pluto. Though its 0.1” disc won’t resolve into anything more than a speck in even the most powerful backyard telescope, knowing just what you’re seeing is part of the thrill of finding the distant world.

Pluto in 2024

The good news is, Pluto reaches opposition for 2024 this week on July 23rd. This means it rises when the Sun sets, and is highest in the sky and well-placed for observation around midnight. 2024 sees Pluto loitering in the zodiacal constellation of Capricornus the Goat, just across the border from its former decade-long residence in Sagittarius.

A wide field finder chart for Pluto in July 2024. Credit: Stellarium

Fun fact: on a leisurely 248-year orbit, Pluto has only moved from the constellation Gemini where it was first discovered by astronomer Clyde Tombaugh in 1930, to its present position.

At the eyepiece, Pluto presents a +14th magnitude dot. You’ll have to star hop through the dense star field to locate the distant world. Sketching or photographing the region to cinch the sighting. Your watching for the slight but discernible motion of the world from one night to the next. Heavens-Above can give you the right ascension/declination search coordinates for Pluto for a given night.

The path of Pluto through late July into August. Stars are plotted down to +14th magntude. Credit: Starry Night.

I remember showing off Pluto to viewers at the Flandrau Observatory in Tucson with the 14” telescope… the world was an easy catch, even from bright downtown urban skies. Use a 6” or larger aperture telescope in your quest.

A Receding World

Pluto passed perihelion on September 5th, 1989. It is now headed out to a distant aphelion 49.3 Astronomical Units (AU or 7.4 billion kilometers) from the Sun next century in February 2114. This means that Pluto varies in brightness from an apparent magnitude of +13.7 near perihelion, to 16 times fainter at magnitude +16.3 near aphelion. Clyde was fortunate that Pluto was headed towards perihelion in the mid-20th century. Otherwise, it might well have eluded discovery (!) Pluto is getting successively fainter with each opposition in the 21st century, so the time to see it for yourself is now.

Pluto from 2016. Credit: Sharin Ahmad From a Dot to a World

Until less than a decade ago, we knew of Pluto’s brightness, distance and orbit… and not much else. One inside joke among astronomers was that Pluto’s size and mass estimates were shrinking at such a rapid rate, that by 1980 it would disappear altogether (spoiler alert: it didn’t). Charon was discovered by astronomer James Christy as a fuzzy blob peeking out from behind its parent body in images. The large moon was found using the 61-inch telescope at the Flagstaff Observatory in 1978. Since then, Hubble revealed four more moons, named Styx, Nix, Kerberos and Hydra.

At +16th magnitude, Charon should be in range of a large dedicated amateur telescope. To date, I’ve only ever seen one convincing potential capture of the large moon. Orbiting once every six days, Charon reaches a separation of about 1”… certainly, near opposition is a key time to try and carry out this extremely challenging observation. Bizarre fact: if astronauts make it to the surface of Pluto by 2107 AD, they can witness a cycle of solar eclipses, courtesy of Charon.

NASA’s New Horizons really opened up the frontier on Pluto and its moons during its historic flyby in 2015. The mission revealed the worlds in dramatic detail. Nearly a decade later, new research is still coming out on the results from the flyby. We now live in an era where we can discuss the formation of Charon, or the geology of Pluto…

New Horizons’ view of Pluto. Credit: NASA/APL/New Horizons

Good luck, on your quest to cross Pluto off of your astronomical life list.

The post Astro-Challenge: Catching Pluto at Opposition 2024 appeared first on Universe Today.

The slow-running movement, in which people meet for unhurried jogs, is booming – but don't be fooled into thinking that if there's no pain, there's no gain