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Genetic analysis shows that there are four varieties of Portuguese man o’ war, or bluebottle, including an Antipodean species that has yet to be named

The largest storm in the Solar System is shrinking and planetary scientists think they have an explanation. It could be related to a reduction in the number of smaller storms that feed it and may be starving Jupiter’s centuries-old Great Red Spot (GRS).

This storm has intrigued observers from its perch in the Jovian southern hemisphere since it was first seen in the mid-1600s. Continuous observations of it began in the late 1800s, which allowed scientists to chart a constant parade of changes. In the process, they’ve learned quite a bit about the spot. It’s a high-pressure region that generates a 16,000 km-wide anticyclonic storm with winds clocking in at more than 321 km per hour. The storm extends down through the atmosphere to a depth of about 250 km below the mainly ammonia cloud tops.

A zoomed-in view of the Great Red Spot based on Juno observations. Courtesy Kevin Gill. Modeling a Shrinking and Growing Great Red Spot

Over the past century, scientists noticed the GRS shrinking, leaving them with a puzzle on their hands. Yale Ph.D. student Caleb Keaveney had the idea that perhaps smaller storms that feed the GRS could play a role in starving it. He and a team of researchers focused on their influence and conducted a series of 3D simulations of the Spot. They used a model called the Explicit Planetary Isentropic-Coordinate (EPIC) model, which is used in studying planetary atmospheres. The result was a suite of computer models that simulated interactions between the Great Red Spot and smaller storms of varying frequency and intensity.

A separate control group of simulations left out the small storms. Then, the team compared the simulations. They saw that the smaller storms seemed to strengthen the Great Red Spot and make it grow. “We found through numerical simulations that by feeding the Great Red Spot a diet of smaller storms, as has been known to occur on Jupiter, we could modulate its size,” Keaveney said.

If that’s true, then the presence (or lack thereof) of those smaller storms could be what’s changing the spot’s size. Essentially, a lot of smaller spots cause it to grow larger. Fewer little ones cause it to shrink. Furthermore, the team’s modeling supports an interesting idea. Without forced interactions with these smaller vortices, the Spot can shrink over a period of about 2.6 Earth years.

Using Earth Storms as a Comparison

The Great Red Spot isn’t the only place in the Solar System that sports such a long-lived high-pressure system. Earth experiences plenty of them, usually called “heat domes” or “blocks.” Most of us are familiar with heat domes because we experience them during the summer months. They happen frequently in the upper atmosphere jet stream that circulates across our planet’s mid-latitudes. We can blame them for some of the extreme weather people experience—such as heat waves and extended droughts. They tend to last a long time, and they are linked to interactions with smaller transient weather such as high-pressure eddies and anticyclones.

Given that the Great Red Spot is an anticyclonic feature, it has interesting implications for similar atmospheric structures on both planets, according to Keaveney. “Interactions with nearby weather systems have been shown to sustain and amplify heat domes, which motivated our hypothesis that similar interactions on Jupiter could sustain the Great Red Spot,” he said. “In validating that hypothesis, we provide additional support to this understanding of heat domes on Earth.”

The Ever-changing Great Red Spot

In addition to the changing size of the Great Red Spot, observers also notice shifts in its color. It’s mainly reddish-orange but has been known to fade to a pinkish-orange hue. The colors suggest some complex chemistry occurring in the region spurred by solar radiation. It has an effect on a chemical compound called ammonium hydrosulfide as well as the organic compound acetylene. That creates a substance called a tholin, which gives a reddish color wherever it exists.

At times the spot has nearly disappeared altogether due to some complex interaction with a feature called the Southern Equatorial Belt (SEB). The SEB is where the spot is located, and when it is bright and white, the spot goes dark. At other times, the reverse color change happens. In some cases, the SEB itself has disappeared at various times. No one is quite sure why this is happening, but it’s one more piece of the Jovian atmospheric puzzle.

These Hubble images of Jupiter taken 11 months apart show the Southern Equatorial Belt has disappeared. Note the presence of the Great Red Spot. Credit: NASA, ESA, M. H. Wong (University of California, Berkeley, USA), H. B. Hammel (Space Science Institute, Boulder, Colorado, USA), A. A. Simon-Miller (Goddard Space Flight Center, Greenbelt, Maryland, USA) and the Jupiter Impact Science Team.

Changes to the Great Red Spot have been studied extensively not just from the ground, but also by spacecraft missions, beginning with Voyager and extending through the Galileo, Cassini, and Juno missions. Each spacecraft used specialized instruments to probe the spot, measure its windspeeds and temperatures, and sample the gas and compounds in the upper atmosphere. All of that data feeds models like the ones used at Yale to model the smaller storms’ contributions to the Great Red Spot’s growth and shrinkage.

For More Information

A New Explanation for Jupiter’s Great, Shrinking “Spot”
Effect of Transient Vortex Interactions on the Size and Strength of Jupiter’s Great Red Spot
Juno and the Great Red Spot

The post Why is Jupiter’s Great Red Spot Shrinking? It’s Starving. appeared first on Universe Today.

Creating fertilizers from organic waste can help reduce the consumption of fossil fuels and promote sustainable production. One way of doing this is through hydrothermal liquefaction (HTL), which converts biomass into biocrude oil through a high-temperature, high-pressure process. Two studies explore the use of a fungal treatment to convert the leftover wastewater into fertilizer for agricultural crops.

According to the ESA’s Near-Earth Objects Coordination Center (NEOCC), 35,264 known asteroids regularly cross the orbit of Earth and the other inner planets. Of these, 1,626 have been identified as Potentially Hazardous Asteroids (PHAs), meaning that they may someday pass close enough to Earth to be caught by its gravity and impact its surface. While planetary defense has always been a concern, the comet Shoemaker-Levy 9 slamming into Jupiter in 1994 sparked intense interest in this field.

In 2022, NASA’s Double-Asteroid Redirect Test (DART) mission successfully tested the kinetic impact method when it collided with Dimorphos, the small asteroid orbiting Didymos. Today, the ESA Space Safety program is taking steps to test the next planetary defense mission – the Rapid Apophis Missin for Space Safety (RAMSES). In 2029, RAMSES will rendezvous with the Near Earth Asteroid (NEA) 99942 Apophis and accompany it as it makes a very close (but safe) flyby of Earth in 2029. The data it collects will help scientists improve our ability to protect Earth from similar objects that could pose an impact risk.

Discovered in 2004, Apophis is an irregularly shaped asteroid measuring about 375 m (410 yards) across. At the time, observations indicated there was a small risk that it would impact Earth in 2029, 2036, or 2068. Given its size and the devastating effect an impact would have, astronomers decided to name it after the Egyptian god of chaos and destruction. While astronomers have since ruled out the possibility of a collision for at least the next century, Apophis will pass within 32,000 km (~19,885 mi) of Earth’s surface on April 13th, 2029.

Radar observations of Apophis rule out future impact. Credit: NASA/JPL-Caltech and NSF/AUI/GBO

At this distance, the asteroid will be close enough to be visible to the naked eye to roughly two billion people across much of Europe, Africa, and parts of Asia. Based on analyses of the size and orbits of all known asteroids, astronomers believe that objects this large pass this close to Earth only once every 5,000 to 10,000 years. The RAMSES spacecraft will rendezvous with Apophis before it makes its closest pass to Earth and follow behind, monitoring it with a suite of scientific instruments to see how Earth’s gravity changes it.

This will consist of conducting before-and-after surveys of the asteroid’s shape, surface, orbit, rotation, and orientation. Based on this comparative analysis, scientists will learn more about how an asteroid’s fundamental characteristics – its composition, interior structure, cohesion, mass, density, and porosity – respond to external forces. These properties are vital for determining how to knock a PHA off course so it does not collide with Earth. Patrick Michel, the Director of Research at the Centre national de la recherche scientifique (CNRS) and the Observatoire de la Côte d’Azur in Nice, explained in an ESA press release:

“There is still so much we have yet to learn about asteroids but, until now, we have had to travel deep into the Solar System to study them and perform experiments ourselves to interact with their surface. For the first time ever, nature is bringing one to us and conducting the experiment itself. All we need to do is watch as Apophis is stretched and squeezed by strong tidal forces that may trigger landslides and other disturbances and reveal new material from beneath the surface.”

The ESA recently secured permission from the Space Safety Program board to begin preparatory work on the mission so it can launch by April 2028. This deadline is necessary, so the mission is to be ready to launch and rendezvous with Apophis in orbit by February 2029. The final decision to commit to the mission will be made at the ESA’s Ministerial Council Meeting in November 2025. In the meantime, NASA has redirected its newly renamed OSIRIS-APEX spacecraft towards Apophis, which will arrive one month after the asteroid makes its flyby.

Apophis orbit diverted by Earth’s gravity – NEO Toolkit Space Safety Apophis orbit diverted by Earth’s gravity, Credit: ESA

Since asteroids are leftover material from the formation of the Solar System (ca. 4.5 billion years ago), this rendezvous is also an opportunity to obtain data that could provide new insights into planetary formation and evolution. This makes the 2029 flyby an extremely rare opportunity for astronomy, asteroid science, planetary defense, and for engaging billions of people worldwide. It will also be an opportunity for international collaboration, as previously demonstrated by the DART and the ESA’s Hera missions – the former redirected Didymos while the latter confirmed a change in orbit.

Last, but not least, the RAMSES mission will test the ability of space agencies to build and deploy an asteroid response quickly. As Richard Moissl, heading ESA’s Planetary Defence Office, explained:

“Ramses will demonstrate that humankind can deploy a reconnaissance mission to rendezvous with an incoming asteroid in just a few years. This type of mission is a cornerstone of humankind’s response to a hazardous asteroid. A reconnaissance mission would be launched first to analyse the incoming asteroid’s orbit and structure. The results would be used to determine how best to redirect the asteroid or to rule out non-impacts before an expensive deflector mission is developed.”

Further Reading: ESA

The post ESA is Building a Mission to Visit Asteroid Apophis, Joining it for its 2029 Earth Flyby appeared first on Universe Today.

Astronauts face multiple risks during space flight, such as microgravity and radiation exposure. Microgravity can decrease bone density, and radiation exposure is a carcinogen. However, those are chronic effects.

The biggest risk to astronauts is fire since escape would be difficult on a long mission to Mars or elsewhere beyond Low Earth Orbit. Scientists are researching how fire behaves on spacecraft so astronauts can be protected.

Scientists from the Center of Applied Space Technology and Microgravity (ZARM) at the University of Bremen are investigating the risks of fire onboard spacecraft. They’ve published a new study in the Proceedings of the Combustion Institute titled “Effect of oxygen concentration, pressure, and opposed flow velocity on the flame spread along thin PMMA sheets.” The lead author is Hans-Christoph Ries.

“A fire on board a spacecraft is one of the most dangerous scenarios in space missions,” said Dr. Florian Meyer, head of the Combustion Technology research group at ZARM. “There are hardly any options for getting to a safe place or escaping from a spacecraft. It is therefore crucial to understand the behavior of fires under these special conditions.”

Since 2016, ZARM has been researching how fire behaves and spreads in microgravity conditions like those in the ISS. Those conditions also include an oxygen level similar to Earth’s, forced air circulation, and ambient pressure similar to Earth’s. NASA has been conducting similar experiments, and now we know that fire behaves differently in microgravity than it does on Earth.

Initially, a fire will burn with a smaller flame and take longer to spread. This is to the fire’s advantage since it won’t be noticed as quickly. Fire also burns hotter in microgravity, meaning that some materials that may not be combustible in normal Earth conditions could burn in spacecraft, creating toxic chemicals in the spacecraft’s air.

Spacecraft for Mars missions will have different environments than the ISS. The ambient air pressure will be lower, which provides two benefits: it makes the spacecraft lighter and also allows astronauts to prepare for external missions more quickly. However, the lower ambient pressure introduces another critical change in the spaceship environment. The oxygen content has to be higher to meet the astronauts’ respiration needs.

In these latest tests, the team at ZARM tested fire in these revised conditions.

PMMA stands for polymethyl methacrylate and is usually called acrylic. It’s a common material used in place of glass because it’s light and shatterproof. The ISS doesn’t use it, but it’s being developed for use in future spacecraft. The Orion capsule uses acrylic fused to other materials for windows, and future spacecraft will likely use something similar.

In their experiments, the researchers lit acrylic glass foils on fire and varied three environmental factors: ambient pressure, oxygen content and flow velocity.

This table from the figure is the test matrix for the experiments. The X’s and the single O indicate flow rates: X = 100 mm/s, O = 30–200 mm/s. Image Credit: Ries et al. 2024.

They used the Bremen Drop Tower to simulate microgravity.

The experiments showed that lower ambient pressure dampens fire. However, higher oxygen content has a more powerful effect. The ISS’s oxygen level is 21%, just as it is on Earth. Future spacecraft with lower ambient pressures will have oxygen levels as high as 35%. That translates into a huge increase in the risk astronauts face from fire. The results show that a fire can spread three times faster than it would under Earth conditions.

“Our results highlight critical factors that need to be considered when developing fire safety protocols for astronautic space missions.”

Dr. Florian Meyer, Combustion Technology research group at ZARM This figure from the study shows a time series of infrared images of the tests. They show fire on an acrylic film under microgravity conditions with 100 mm/second airflow, 75 kPa, and 28.3% oxygen. The white dashed lines show the contour of the acrylic sample. The green dotted lines are the evaluation lines used to measure the fire’s propagation rate. In panel b, the pink horizontal bar below the propagation front is the igniter. Image Credit: Ries et al. 2024.

We all know increased airflow spreads fire faster; that’s why we blow on a small flame to create a larger fire. Increased airflow delivers more oxygen, increasing combustion, so increased airflow in a higher-oxygen atmosphere creates a dangerous situation for astronauts.

“Our results highlight critical factors that need to be considered when developing fire safety protocols for astronautic space missions,” said Dr. Florian Meyer. “By understanding how flames spread under different atmospheric conditions, we can mitigate the risk of fire and improve the safety of the crew.”

The post The Most Dangerous Part of a Space Mission is Fire appeared first on Universe Today.

The way oil drops break up at the water's surface means some oil may not get cleaned up after a spill.

As the number of major utility-scale ground solar panel installations grows, concerns about their impacts on natural hydrologic processes also have grown. However, a new study by Penn State researchers suggests that excess runoff or increased erosion can be easily mitigated -- if these 'solar farms' are properly built.

Retinol, which is commonly added to anti-ageing skincare products, may improve hydration by interacting with bacteria on the skin

When a massive star dies in a supernova explosion, it’s not great news for any planets or stars that happen to be nearby. Generally, the catastrophic event crisps nearby worlds and sends companion stars careening through space. So, astronomers were pretty surprised to find 21 neutron stars—the crushed stellar cores left over after supernova explosions—orbiting in binary systems with Sun-like stars.

A team led by Caltech’s Kareem El-Badry detected these cosmic oddities using observations made by the European Space Agency’s Gaia mission. Its astrometrical data revealed “wobbles” in the orbits of the Sun-like companions. The team then followed up with spectral observations of the objects. Essentially, this work helped uncover a new population of what the team terms “dark” neutron stars still in orbital dances with their sunlike partners. Now the trick is to explain why these unusual pairs exist, according to El-Badry.

“We still do not have a complete model for how these binaries form,” he said. “In principle, the progenitor to the neutron star should have become huge and interacted with the solar-type star during its late-stage evolution.”

Astronomers have discovered 21 stars like our Sun in orbit around neutron stars (formed in supernova explosions). The European Space Agency’s Gaia mission detected this wobble by observing the orbits of the Sun-like stars (yellow dots) for three years. The Sun-like stars are green in this animation, and the neutron stars (and their orbits) are purple. Credit: Caltech/Kareem El-Badry Surviving a Supernova?

It seems counterintuitive to think of the nearby star surviving the nearby catastrophe. The process itself begins as the massive progenitor star ages and expands. That pushes the smaller star around. Just before the supernova occurred, the dying star probably engulfed the companion for a time. Some theories suggest that the engulfment itself could destroy the smaller star. Others say that it affects the star but doesn’t completely obliterate it.

At some point, the larger star’s core collapses when it runs out of fuel. All the other layers come crashing down on the core. The temperatures and pressures in the event compress what’s left of the core into a ball of neutrons. Then, the outer layers rebound off the core and blast out into space. That’s the part we see as the supernova explosion. The outburst should eject it from the system if there’s still a companion star. However, for these strange binaries, that didn’t happen. The neutron star and a companion remain.

Now it’s El-Badry’s team task to figure out why. “The discovery of these new systems shows that at least some binaries survive these cataclysmic processes even though models cannot yet fully explain how,” he said. In a paper about the finding, the team also suggests that they cannot rule out that the neutron stars may be ultramassive white dwarfs or white dwarf binaries.

The Search for Neutron Stars and their Companions

The Gaia mission aims to scan the sky and look for “wobbles” in the motions of more than a billion stars. The orbits of planets around the stars cause wobbles. However, the gravitational tug of nearby black holes, neutron stars, or more massive stars also induces them.

Neutron stars are massive balls of neutrons about 20 km across but denser than the Sun. They’re created as the collapsing stellar layers crush the core of the supernova progenitor star. As the neutron star and its companion orbit around a common center of mass, the neutron star tugs on its companion and that makes it shift back and forth—creating the telltale “wobble”. Gaia detected those wobbles, and then scientists used data from follow-up observations at several ground-based telescopes, including the W. M. Keck Observatory on Maunakea, Hawai‘i; La Silla Observatory in Chile; and the Whipple Observatory in Arizona. That gave them more information about the masses and orbits of the hidden neutron stars.

Now, there have been neutron stars in orbit with other Sun-like stars, those orbits have been pretty tight and close-in. In those cases, the mass transfer between the two companions makes the neutron star brighter in X-ray or radio wavelengths. That’s not true for the 21 systems El-Badry’s team studied. They are much farther apart in wider orbits. This limits how much material the neutron star can steal from its companion. As a result, those objects are dark and quiet. “These are the first neutron stars discovered purely due to their gravitational effects,” El-Badry said.

An animation of a binary star system containing a neutron star created in a supernova and a Sun-like companion. Credit: Caltech/R. Hurt (IPAC) Tracing the Tale from Supernova to Binary

So, now astronomers have a population of neutron star/Sun-like star binaries to explain. Now, the team will work to figure out the real story of why these rare pairings still exist. “We estimate that about one in a million solar-type stars is orbiting a neutron star in a wide orbit,” El-Badry said.

He’s also interested in similar matchups between dormant (and largely invisible) black holes and Sun-like stars. There are two that he knows about, including one called Gaia BH1, which is only 1,600 light-years away from us. The fact that these odd couples also exist opens up a lot of questions. “We don’t know for sure how these black hole binaries formed either,” El-Badry said. “There are clearly gaps in our models for the evolution of binary stars. Finding more of these dark companions and comparing their population statistics to predictions of different models will help us piece together how they form.”

For More Information

Sun-Like Stars Found Orbiting Hidden Companions
A Population of Neutron Star Candidates in Wide Orbits from Gaia Astrometry

The post Stars Can Survive Their Partner Detonating as a Supernova appeared first on Universe Today.

A jiggling robot has revealed the ideal vibrating speed to free jumbled fibres

A new camera could prevent companies from collecting embarrassing and identifiable photos and videos from devices like smart home cameras and robotic vacuums. It's called PrivacyLens.

A new camera could prevent companies from collecting embarrassing and identifiable photos and videos from devices like smart home cameras and robotic vacuums. It's called PrivacyLens.

Europe's next big space mission -- a telescope that will hunt for Earth-like rocky planets outside of our solar system -- is on course to launch at the end of 2026. PLATO, or PLAnetary Transits and Oscillations of stars, is being built to find nearby potentially habitable worlds around Sun-like stars that we can examine in detail.

A new study suggests that the U.S. government's push to increase heavy-duty trucks' energy efficiency could encourage more shipping by truck instead of rail, reducing the policies' anticipated effectiveness by 20%.

So far, only about ten intermediate-mass black holes have been discovered in the entire universe. The newly identified black hole causes surrounding stars in a cluster to move in an unexpectedly orderly way.

The flowless zinc-bromine battery (FLZBB) is a promising alternative to flammable lithium-ion batteries due to its use of non-flammable electrolytes. However, it suffers from self-discharge due to the crossover of active materials, generated at the positive graphite felt (GF) electrode, to the negative electrode, significantly affecting performance. Now, researchers have developed a novel nitrogen-doped mesoporous carbon-coated GF electrode that effectively suppresses self-discharge. This breakthrough can lead to practical applications of FLZBB in energy storage systems.

Researchers have developed a new formal description of internal world models, thereby enabling interdisciplinary research. Internal world models help to make predictions about new situations based on previous experience and to help find one's bearings. The new formalized view helps to compare world models of humans, animals and AI and to eliminate deficits.

By harnessing the power of machine learning, researchers have constructed a framework for analyzing what factors most significantly contribute to a species' genetic diversity.

The VIPER moon rover was due to launch in 2025 but NASA has suddenly cancelled it, citing budgetary issues, despite the spacecraft being fully built

The UK had no plans for preventing or limiting the spread of a covid-19-like infection because it assumed the next pandemic would be caused by an unstoppable flu virus, an inquiry into the outbreak has revealed