Category: 7. Science

3I/ATLAS is only the third object of its kind ever observed, following the interstellar asteroid 1I/ʻOumuamua in 2017 and the interstellar comet 2I/Borisov in 2019.

3I/ATLAS is currently around 670 million km (420 million miles) from the Sun and will make its closest approach in October 2025, passing just inside the orbit of Mars.

It is thought to be up to 20 km (12 miles) in diameter and is traveling roughly 60 km per second (37 miles per second) relative to the Sun.

It poses no danger to Earth, coming no closer than 240 million km (150 million miles) — over 1.5 times the distance between Earth and the Sun.

3I/ATLAS is an active comet; if it heats up sufficiently as it nears the Sun, it could begin to sublimate — a process in which frozen gases transform directly into vapor, carrying dust and ice particles into space to form a glowing coma and tail.

However, by the time the comet reaches its closest point to Earth, it will be hidden behind the Sun. It is expected to reappear by early December 2025, offering astronomers another window for study.

“Spotting a possible interstellar object is incredibly rare, and it’s exciting that our Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope caught it,” said Professor John Tonry, an astronomer at the University of Hawai’i.

“These interstellar visitors provide an extremely interesting glimpse of things from solar systems other than our own.”

“Quite a few come through our inner Solar System each year, although 3I/ATLAS is by far the biggest to date.”

“The chances of one actually hitting the Earth are infinitesimal, less than 1 in 10 million each year, but ATLAS is continually searching the sky for any object that might pose a problem.”

Astronomers are using telescopes in Hawai’i, Chile, and other countries to monitor the comet’s progress.

They are interested in learning more about this interstellar visitor’s composition and behavior.

“What makes interstellar objects like 3I/ATLAS so extraordinary is their absolutely foreign nature,” ESA astronomers said in a statement.

“While every planet, moon, asteroid, comet and lifeform that formed in our Solar System shares a common origin, a common heritage, interstellar visitors are true outsiders.”

“They are remnants of other planetary systems, carrying with them clues about the formation of worlds far beyond our own.”

“It may be thousands of years until humans visit a planet in another solar system and interstellar comets offer the tantalizing opportunity for us to touch something truly otherworldly.”

“These icy wanderers offer a rare, tangible connection to the broader galaxy — to materials formed in environments entirely unlike our own.”

“To visit one would be to connect humankind with the Universe on a far greater scale.”

As humanity looks to the stars, the dwarf planet Sedna presents an intriguing challenge for scientists and adventurers alike. Located billions of miles from the Sun, Sedna offers a rare opportunity to explore the outer reaches of our solar system. With its next closest approach to the Sun set for 2076, researchers are keen to capitalize on this chance to gather invaluable data about the early solar system. Recently, a team of scientists has proposed utilizing nuclear propulsion and solar sails to reach Sedna in a mere seven years, a feat that could revolutionize space exploration.

Flying to Sedna with Two Experimental Spacecraft Concepts

Back in 2003, astronomers made a groundbreaking discovery when they identified Sedna, a distant object orbiting the Sun far beyond Pluto. Named after the Inuit goddess of the ocean, Sedna provided a tantalizing glimpse into the mysteries of the outer solar system. With a staggering orbital period of 10,000 years, it travels billions of miles from the Sun. However, its upcoming perihelion in 2076 offers a window of opportunity for exploration.

In a recent paper published on arXiv, a team of researchers from Italy outlined two pioneering propulsion concepts that could significantly cut travel time to Sedna. The first involves a nuclear fusion rocket engine, while the second explores the potential of a solar sail. These innovative technologies promise to reduce the journey to Sedna by more than 50%, making it feasible to reach the dwarf planet in just seven to ten years. At its closest approach, Sedna will be within 7 billion miles of the Sun, a distance that might be surmountable with these advanced spacecraft.

“We’ve Never Seen Them This Close”: NASA Tracks Five Giant Asteroids Skimming Past Earth in Record-Breaking Flyby Cluster

Nuclear Propulsion and Solar Sailing

The first of the proposed technologies is the Direct Fusion Drive (DFD) rocket engine, currently under development at Princeton University’s Plasma Physics Laboratory. This engine aims to generate both thrust and electrical power through controlled nuclear fusion reactions. The DFD presents a promising alternative to conventional propulsion methods, offering a high thrust-to-weight ratio and continuous acceleration. However, several engineering challenges remain, such as plasma stability and heat dissipation, which need to be addressed before it can be deployed in deep-space missions.

On the other hand, the concept of solar sailing utilizes the Sun’s energy to propel a lightweight spacecraft at high speeds. This method gained traction with the successful mission of LightSail 2 by The Planetary Society in 2019. In this approach, a large sail captures photons from the Sun, providing thrust without the need for heavy fuel. The Italian researchers propose enhancing this concept by coating the sails with a material that releases molecules when heated, further increasing propulsion through thermal desorption. This could enable a solar sail mission to reach Sedna in just seven years, although it would be limited to a flyby.

“Mars Lost Its Water Here”: NASA Captures Ancient Blast That May Explain How the Red Planet Turned Into a Dusty Wasteland

The Strategic Importance of Sedna Exploration

Exploring Sedna is not just about reaching a distant celestial body; it holds strategic significance in understanding the early solar system. By studying Sedna, scientists hope to uncover clues about the formation and evolution of our solar neighborhood. Sedna’s remote and icy environment may contain preserved materials from the solar system’s infancy, offering insights into the building blocks of planets and other celestial bodies. Such knowledge could reshape our understanding of planetary science and the processes that govern the cosmos.

Moreover, the technological advancements required for a mission to Sedna could have far-reaching implications for future space exploration. The development of nuclear propulsion and solar sailing technologies could pave the way for more ambitious missions to even more distant objects, potentially leading to human exploration beyond the current boundaries of our solar system. As we push the frontiers of space travel, Sedna stands as a gateway to the unknown, beckoning us to venture further into the universe.

“Moon Time Is American Time”: NASA Moves to Set Lunar Time Zone as U.S. Races to Cement Dominance on the Moon

The Challenges and Opportunities Ahead

While the prospect of reaching Sedna in seven years is exciting, it is not without its challenges. Developing and testing the necessary technologies will require significant time, resources, and international collaboration. Overcoming the engineering hurdles associated with nuclear propulsion and solar sails is critical to the success of the mission. Additionally, the mission will need to navigate the logistical complexities of deep-space travel, including communication, navigation, and power generation.

Despite these challenges, the potential rewards of a successful mission to Sedna are immense. By pushing the limits of current space technology, we can open new avenues for exploration and scientific discovery. The pursuit of Sedna is a testament to human ingenuity and our relentless quest for knowledge. As we stand on the brink of this new frontier, one question remains: what other secrets does the universe hold, waiting to be uncovered by our pioneering spirit?

Our author used artificial intelligence to enhance this article.

Did you like it? 4.5/5 (25)

An astronaut aboard the International Space Station has shared a striking photo of what is known as a Transient Luminous Event seen above a thunderstorm over Mexico and the Desert Southwest earlier in the week.

NASA astronaut Nichole “Vapor” Ayers posted the image on social media and said, “Just. Wow. As we went over Mexico and the U.S. this morning, I caught this sprite.”

Sprites are a type of TLE, which create brilliant flashes of light high above powerful thunderstorms and are difficult to observe from the ground.

There is some debate on whether what she captured is surely a sprite or what is known as a gigantic jet – both are part of the TLE phenomena.

SEE RENDERINGS OF SPACE STATION TO BE BUILT AROUND THE MOON

According to NOAA, sprites are often triggered by positive cloud-to-ground lightning strikes, which produce an electric field that extends miles above a thunderstorm into the upper atmosphere.

The phenomenon appears mostly red in color, lasts only a fraction of a second and occurs so high up in the atmosphere that it is rarely visible to the human eye – unless, of course, you are orbiting some 250 miles above Earth’s surface.

“Sprites are TLEs, or Transient Luminous Events, that happen above the clouds and are triggered by intense electrical activity in the thunderstorms below. We have a great view above the clouds, so scientists can use these types of pictures to better understand the formation, characteristics, and relationship of TLEs to thunderstorms,” Ayers explained on social media.

Gigantic jets begin inside the anvil and reach through the cloud up to the ionosphere, which represents what Ayers might have witnessed.

Why some lightning bolts trigger sprites while others do not is still poorly understood by the scientific community.

Other related phenomena include elves, blue jets and ghosts, all of which are known TLEs, and occur well above Earth’s surface in the stratosphere, mesosphere and even the thermosphere.

SEE THE OBJECTS HUMANS LEFT BEHIND ON THE MOON

Ayers is currently stationed aboard the ISS as part of NASA’s SpaceX Crew-10 mission, which launched in March and is expected to remain in outer space through at least August.

During the astronauts’ time aboard the space observatory, the crew will conduct hundreds of scientific experiments, including testing the flammability of material and studies examining the physiological and psychological effects of space on the human body.

Read more at FOXWeather.com. 

Led by the European Research Council Synergy Grant project Into the Blue – i2B, the research team studied sediment cores collected from the seafloor of the central Nordic Seas and Yermak Plateau, north of Svalbard. These cores hold tiny chemical fingerprints from algae that lived in the ocean long ago. Some of these algae only grow in open water, while others thrive under seasonal sea ice that forms and melts each year.

“Our sediment cores show that marine life was active even during the coldest times,” said Jochen Knies , lead author of the study, based at UiT The Arctic University of Norway and co-lead of the Into The Blue – i2B project. “That tells us there must have been light and open water at the surface. You wouldn’t see that if the entire Arctic was locked under a kilometre-thick slab of ice.”

One of the key indicators the team looked for was a molecule called IP₂₅, which is produced by algae that live in seasonal sea ice. Its regular appearance in the sediments shows that sea ice came and went with the seasons, rather than staying frozen solid all year round.

Simulating ancient Arctic climates

To test the findings based on the geological records, the research team used the AWI Earth System Model – a high-resolution computer model – to simulate Arctic conditions during two especially cold periods: the Last Glacial Maximum around 21,000 years ago, and a deeper freeze about 140,000 years ago when large ice sheets covered a lot of the Arctic.

“The models support what we found in the sediments,” said Knies. “Even during these extreme glaciations, warm Atlantic water still flowed into the Arctic gateway. This helped keep some parts of the ocean from freezing over completely.”

The models also showed that the ice wasn’t static. Instead, it shifted with the seasons, creating openings in the ice where light could reach the water—and where life could continue to thrive. This research not only reshapes our view of past Arctic climates but also has implications for future climate predictions. Understanding how sea ice and ocean circulation responded to past climate extremes can improve models that project future changes in a warming world.

“These reconstructions help us understand what’s possible—and what’s not—when it comes to ice cover and ocean dynamics,” said Gerrit Lohmann , co-author of this study, based at Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) and co-lead of Into The Blue – i2B. “That matters when trying to anticipate how ice sheets and sea ice might behave in the future.”

Re-thinking the giant ice shelf theory

Some scientists have argued that features on the Arctic seafloor suggest that a huge, grounded ice shelf once covered the entire ocean. But this new study offers another explanation.

“There may have been short-lived ice shelves in some parts of the Arctic during especially severe cold phases,” said Knies. “But we don’t see any sign of a single, massive ice shelf that covered everything for thousands of years.”

One possible exception could have occurred about 650,000 years ago, when biological activity in the sediment record dropped sharply. But even then, the evidence points to a temporary event, not a long-lasting frozen lid over the Arctic.

Understanding the Arctic’s future

The study sheds new light on how the Arctic has behaved under extreme conditions in the past. This matters because the Arctic is changing rapidly today. Knowing how sea ice and ocean circulation responded to past climate shifts helps scientists understand what might lie ahead.

“These past patterns help us understand what’s possible in future scenarios,” said Knies. “We need to know how the Arctic behaves under stress—and what tipping points to watch for – as the Arctic responds to a warming world.”

The full paper, “Seasonal sea ice characterized the glacial Arctic–Atlantic gateway over the past 750,000 years”, is available in Science Advances.

This research is part of the European Research Council Synergy Grant project Into the Blue – i2B and the Research Council of Norway Centre of Excellence, iC3: Centre for ice, Cryosphere, Carbon, and Climate .

Poke around a British rockpool and you may spot a shell shuffling over the sand. Inside is a hermit crab – an animal that spends much of its life testing the outside world before deciding whether it is safe to venture forth.

New research from the University of Plymouth reveals that the speed of that decision, a trait biologists call boldness, hinges on a crab’s built-in sensory toolkit.

The study focuses on microscopic hair-like structures called sensilla that pepper the claws of Pagurus bernhardus, a common UK species.

By counting those hairs on dozens of individuals and matching the totals to behavior in the lab, the team discovered a clear pattern: more sensilla equals faster recovery from a startle response.

Hermit crabs so equipped are not only bolder, they are also more predictable – showing similar, rapid emergence times across repeated tests.

Measuring crab response times

The experiment began with a simple but telling ritual. Researchers placed each crab in a small tank and gently startled it with a puff of water or a light tap on the shell.

That cue mimics the sudden pressure wave generated by a predator or rolling wave, prompting the animal to yank its legs and antennae inside its borrowed shell. The team then timed how long it took for eye stalks and claws to reappear.

About a third of a second is considered lightning fast in hermit-crab terms; several minutes, positively timid. Over repeated trials, certain individuals consistently clocked shorter hideouts, indicating a stable personality trait rather than random chance.

“I was especially intrigued by how they used their claws and other sensory appendages, such as their antennae, in their explorations and when re-emerging from their shell,” said lead author Ari Drummond, a PhD student at the University of Plymouth.

That curiosity led to the hunch that claws might act as information-gathering probes, letting crabs “sniff” the water for chemical cues or feel subtle currents that betray lurking threats.

Claw molts reveal sensors

Linking behavior to anatomy required patience. Hermit crabs, like all crustaceans, periodically molt. During this process, they shed the outer exoskeleton, including the thin cuticle covering each sensillum.

Drummond and colleagues waited for each test subject to molt naturally, collected the discarded claw tissue, and examined it under a scanning electron microscope.

The high-resolution images looked like alien landscapes – ridged terrain studded with evenly spaced bristles. Each bristle is a sensillum, connected to nerve cells that detect touch, water movement, or dissolved chemicals.

By tracing and counting every sensillum in the images, the team created a detailed sensory map for each crab. This noninvasive method marked a major advance over earlier studies, which often required removing limbs.

Analysis revealed striking variation: some claws sported 50 percent more sensilla than others of similar size. When the researchers plotted those numbers against startle data, the trend became unmistakable. Bolder hermit crabs have more sensilla on the claw surface.

Bolder crabs have more hairs

Why would extra sensory hairs translate into courage? The authors propose that better input reduces uncertainty. With richer information about water chemistry or microcurrents, a crab can judge threats more accurately and resume foraging sooner.

That efficiency, in turn, may feed back into survival and reproductive success, favoring individuals who “invest” in sensory hardware.

They call the concept the “sensory investment syndrome.” It’s a hypothesis linking an animal’s personality – here, boldness – to the resources it allocates to senses. If confirmed across other species, it could reshape how biologists think about behavioral diversity in nature.

“We’ve known for a long time that individual animals of the same species can show consistent behavioral differences from one another,” said senior author Mark Briffa, a professor at Plymouth.

“Our new research suggests that in hermit crabs, some of this variation may be linked to how individuals sense the world around them.”

In his opinion, similar mechanisms might operate in insects, fish, or even mammals, where variation in eye size, whisker density, or olfactory receptors could underpin consistent behavioral tendencies.

Crab survival starts with sensing

Hermit crabs face mounting challenges: coastal pollution, rising temperatures, and habitat disturbance all alter the sensory landscape of rockpools. Understanding how these creatures sense and decide may reveal which populations are most at risk from environmental change.

“In a world where environments and species are increasingly at risk from human impacts, it is essential that we gain a better understanding of what information animals detect, how they use that information and then respond to stay alive,” Drummond said.

Future work will test what each sensillum detects and whether diet, growth, or shell choice affects hair abundance.

For now, the takeaway is clear: in the miniature dramas playing out between tide and shore, knowledge is power – delivered through a forest of microscopic hairs on a tiny claw.

The study is published in the journal Proceedings of the Royal Society B.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–

Mitochondria are the body’s “energy factories,” and their proper function is essential for life. Inside mitochondria, a set of complexes called the oxidative phosphorylation (OxPhos) system acts like a biochemical assembly line, transforming oxygen and nutrients into usable energy.

Now, the study, led by the GENOXPHOS group at the Spanish National Centre for Cardiovascular Research (CNIC) and the Biomedical Research Networking Centre in the area of Frailty and Healthy Ageing (CIBERFES), and directed by Dr. José Antonio Enríquez, has revealed how this system evolved over millions of years-from the first vertebrates to modern humans. “Understanding this evolution helps explain why some genetic mutations cause rare but serious diseases that affect the OxPhos system,” say José Luis Cabrera the leading author of the study.

Published in Cell Genomics, the study describes the molecular evolutionary strategies of the OxPhos system, the main site of metabolic and energy integration in the cell. It also shows how this information can be used to identify mutations that cause disease.

Working in collaboration with Fátima Sánchez-Cabo, head of the CNIC Computational Systems Biomedicine group, the researchers analyzed the interaction between the two types of DNA that encode OxPhos proteins: nuclear DNA (inherited from both parents) and mitochondrial DNA (inherited only from the mother).

The OxPhos system, explains José Antonio Enríquez-head of the CNIC Functional Genetics of the Oxidative Phosphorylation System (GENOXPHOS) group-comprises five large protein complexes: four that transport electrons and one, called ATP synthase, that produces ATP, the cell’s molecular “fuel.”

These complexes can work individually or in combination, depending on the cell’s energy needs. Together, they are made up of 103 proteins encoded by two different genomes: nuclear and mitochondrial. While nuclear DNA changes slowly over time and gains variation through genetic mixing during reproduction, mitochondrial DNA evolves much more rapidly but is passed only through the maternal line.”

Dr. José Antonio Enríquez, GENOXPHOS Lab, CNIC

Dr. Cabrera adds that the proteins encoded by mitochondrial DNA form the core of the respiratory complexes, “so proper function depends on precise compatibility between the nuclear and mitochondrial components.”

The study also introduces an innovative new tool: ConScore, a predictive index that assesses the clinical relevance of mutations in the 103 OxPhos proteins. “ConScore is based on the evolutionary divergence of these proteins across vertebrates-including primates and other mammals-and complements human population genetic data,” says Enríquez.

The authors affirm that ConScore provides a new framework for interpreting potentially pathogenic mutations, opening the door to improved diagnosis and treatment of mitochondrial diseases.

Ultimately, the researchers conclude, this study not only advances our understanding of how human cells evolved, but also brings us closer to new solutions for patients with rare genetic diseases.