Category: 7. Science

Our home galaxy, the Milky Way, is a magnificent spiral galaxy with a disc of stars spanning over 100,000 light-years, according to NASA reports. Earth is located within one of its spiral arms, about halfway from the galactic centre, and our solar system takes roughly 240 million years to complete a single orbit around it. From our vantage point on Earth, the Milky Way appears as a faint, milky band stretching across the night sky, a feature that inspired its name. The galaxy is part of the Local Group, a collection of more than 50 galaxies, ranging from tiny dwarf galaxies to the massive Andromeda Galaxy. This Local Group itself is a component of the enormous Laniakea supercluster, a vast network of galaxies spanning hundreds of millions of light-years.

From stars to black holes: Things you didn’t know about Milky Way

The Milky Way is a spiral galaxy and our cosmic home, containing hundreds of billions of stars, including the Sun. From Earth, it looks like a faint, milky band across the night sky. At its centre lies a supermassive black hole, and it is part of the Local Group of galaxies, according to NASA.1. The Milky Way is warped

The Milky Way is shaped like a giant disc, roughly 120,000 light-years across, with a central bulge about 12,000 light-years wide. It is not completely flat; instead, it is slightly warped. This warping happens because of gravitational pulls from nearby galaxies, especially the Large and Small Magellanic Clouds. Think of it like stretching and pulling on a trampoline, these nearby galaxies tug at the Milky Way, bending its edges. This makes our galaxy look a bit twisted rather than perfectly smooth, a feature shared with some other spiral galaxies in the Universe.2. It has an invisible halo

Around the Milky Way is an invisible halo made mostly of dark matter, which cannot be seen through telescopes or cameras. Dark matter makes up about 90% of the galaxy, while visible matter like stars, gas, and dust makes up the remaining 10%. This invisible halo is very important because it keeps stars moving fast enough to stay in orbit around the galaxy. Without dark matter, stars, especially those far from the centre, would drift away into space. Scientists study the halo by observing the movement of stars and gas.3. The galaxy has over 200 billion starsThe Milky Way is home to over 200 billion stars, ranging from tiny, dim red dwarfs to massive, bright blue stars. Our Sun is just one of these stars. Despite its size, the Milky Way is considered a medium-sized galaxy. For comparison, the largest galaxy known, IC 1101, contains more than 100 trillion stars, almost 500 times more than the Milky Way! Each star in our galaxy has its own system of planets, moons, and other celestial bodies, making the Milky Way incredibly full of potential worlds.4. Dusty and gassy

About 10-15% of the Milky Way’s visible matter is made of gas and dust, while the rest is stars. The dust is very fine, like tiny grains of sand, and spreads throughout the galaxy. When we look at the night sky, especially far from city lights, we can sometimes see the Milky Way as a faint, milky band. This band is made mostly of stars and dust packed so closely together that they look like a soft glow. The dust and gas are also important because they form new stars and planets.5. It was formed from other galaxies

The Milky Way did not form alone, it grew by merging with smaller galaxies over billions of years. When a smaller galaxy collides or is absorbed, its stars and gas become part of the Milky Way. Right now, the galaxy is pulling in the Canis Major Dwarf Galaxy, adding its stars to our spiral arms. These mergers are normal in the Universe and help the Milky Way grow bigger, create new stars, and change its shape over time.6. We cannot photograph the entire galaxy

Even though we live inside the Milky Way, we cannot take a picture of the whole galaxy. Our solar system is about 26,000 light-years from the galactic centre, so we only see a small part of it from the inside. Any pictures you have seen of the Milky Way as a full spiral are either artist’s drawings or images of other similar galaxies. Scientists use telescopes and computer models to imagine what the Milky Way looks like as a whole.7. A supermassive black hole resides at the centre

At the very centre of the Milky Way is a supermassive black hole called Sagittarius A*. It is enormous, about 14 million miles across, and has a mass roughly 4 million times that of our Sun. Around it is a dense disc of gas and stars, and the black hole’s gravity keeps the galaxy’s central stars moving. Supermassive black holes like this are found at the centres of many large galaxies and play a key role in their formation and evolution.8. Almost as old as the universeThe Milky Way is extremely old. Scientists estimate it is about 13.6 billion years old, while the Universe itself is around 13.7 billion years old. This means the Milky Way formed shortly after the Big Bang. Its main parts, like the central bulge and halo, formed early, but the disc and spiral arms took shape 10–12 billion years ago. Studying the galaxy’s age helps scientists understand how galaxies grow and evolve over billions of years.9. Part of the Virgo Supercluster

The Milky Way is not alone in space. It is part of the Virgo Supercluster, which contains at least 100 galaxy groups and clusters and spans roughly 110 million light-years. This supercluster is itself part of a larger structure called Laniakea, which links together thousands of galaxies. Being part of these massive cosmic structures shows that galaxies are connected on a huge scale, forming the intricate web of the Universe.10. The Milky Way is constantly movingThe Milky Way is not stationary; it is moving through space at an incredible speed. Together with the Local Group of galaxies, it travels at about 600 km/s (2.2 million km/h). Scientists measure this motion using the Cosmic Microwave Background, the faint radiation left over from the Big Bang. Even though we cannot feel it, this motion means the galaxy is constantly changing its position and orientation in the Universe.Also read | NASA discovers new shape of the solar system’s bubble: Not a comet, but a croissant

If you’re feeling sore from a run or gym session, you might wonder whether it’s better to push through or give your body a rest.

This achy or stiff feeling in your muscles after exercise is known as “delayed onset muscle soreness” (DOMS). Soreness usually sets in within the first 12–24 hours after your exercise session, and often peaks 24–72 hours after.

In most instances, DOMS will disappear completely in three to five days. But what should you do in the meantime? Is it OK to exercise if you’re still sore? Here’s what the evidence says.

Why do muscles get sore after a workout?

When you exercise, tiny tears (also called “microtears”) occur in your muscles. Then, as your body floods the area with fluids and nutrients to repair them, it causes inflammation. This is part of the normal recovery process, and helps stimulate increases in muscle strength and size.

But inflammation also stimulates pain receptors, which makes you feel sore in the days after your workout.

How sore you feel will depend on the exercise you do. DOMS is more likely when you haven’t exercised for a while, you do a new type of exercise, or it puts a large load on your muscles (for example, weight training or running).

Basically, it’s your muscles’ response to doing something more demanding or challenging than usual.

The more often you do the same type of exercise, the less likely you are to feel sore.

Should you be sore after every workout?

Muscle soreness is completely normal, especially if you are new to exercise. But it’s not necessarily a good indicator of progress.

All it really tells us is that our body is adapting to a new form of exercise or a sudden increase in load.

It doesn’t tell us whether or not that exercise was effective at building muscle and improving fitness – especially if you’ve been exercising consistently and gradually increasing your load or frequency.

For example, someone who runs regularly is unlikely to feel sore after a single running session, but it will still improve their fitness.

Similarly, if you lift weights regularly, using heavier weights than usual will at most give you only mild DOMS. Yet each training session will still be helping you improve strength and build muscle.

So, should I exercise if I am still sore?

It depends if you’re concerned about injury or performance.

Exercising while recovering from DOMS won’t hurt you. But some evidence suggests your strength and performance may decline when you’re sore. This means you probably won’t be able to lift as much or run as fast while you have DOMS.

Some research has also shown that muscle damage can negatively affect balance. This might increase your risk of falling or even getting an injury such as a sprained ankle.

Another study found soreness can also reduce your skill performance (in this case basketball shooting accuracy). So you might notice an impact if you’re exercising with certain performance goals in mind.

What about rest days?

Taking days off for recovery in between exercise sessions doesn’t seem to make much difference for long-term progress building strength or fitness.

Research has compared training on consecutive days – for example, Monday, Tuesday and Wednesday – with non-consecutive days – Monday, Wednesday, Friday.

And it doesn’t seem to make a difference.

For example, one study had two groups perform the same full-body weight training routine for seven weeks, either on three consecutive or three non-consecutive days. Both groups saw similar improvements in building muscle strength and size.

Similarly, another study compared two groups of cyclists doing the same high-intensity interval training program routine on three consecutive or three non-consecutive days. After three weeks both groups showed the same overall improvements in aerobic fitness and time trial performance.

These were relatively short-term studies. So it’s also possible that over the course of a training year, taking a rest day here and there will help maintain motivation and avoid injury.

Bottom line

While you’ll probably feel slower or stiffer, exercising with sore muscles won’t hurt you and is unlikely to hinder your training progress.

However, you might want to avoid exercises that rely on balance – such as intense jumping and landing movements – as your risk of injury could be slightly greater.

If you are really sore, there is some evidence massage or even an ice bath might help you recover, although the effect is small.

And while muscle soreness is normal, it’s still important to listen to your body. Never push through intense discomfort or pain, as this could be the sign of an injury.

You should talk to a doctor if:

• your muscles feel extremely sore and it lasts for more than seven days
• you have visible muscle bruising where the muscle is sore
• you have sharp pain.

According to a recent study, events geologists use to distinguish transitions between geological chapters in Earth’s story follow a hidden hierarchical pattern, one that could shed light on both past and future tumult.

“Geological time scales may look like tidy timelines in textbooks, but their boundaries tell a much more chaotic story,” says study co-author Andrej Spiridonov, a geologist and paleontologist at Vilnius University in Lithuania.

“Our findings show that what seemed like uneven noise is actually a key to understanding how our planet changes, and how far that change can go,” Spiridonov says.

Related: The Human Epoch Doesn’t Officially Exist. But We Know When It Began.

The history of our planet is full of upheavals, some dramatic enough to trigger whole new blocks of geological time. This includes changes between comparatively short divisions like ages and epochs, as well as much longer units of time like eras and eons.

The asteroid that decimated the dinosaurs 66 million years ago, for example, caused enough overall disruption to help conclude the Mesozoic Era and kick off the Cenozoic. The Cenozoic, which continues today, is further subdivided into three periods and at least seven epochs.

The processes driving these transitions are complicated, yielding variable intervals of relative stability punctuated by apparently unpredictable calamities of different types and magnitudes.

Yet there are signs this may be less capricious than it seems.

The new study focuses on the current Phanerozoic Eon, which dates back around 540 million years and includes the Cenozoic, Mesozoic, and Paleozoic eras. It’s one of Earth’s four eons so far, preceded by the Proterozoic, Archean, and Hadean.

Spiridonov and his colleagues used time divisions established by the International Commission on Stratigraphy, but also analyzed boundaries based on stratigraphic ranges of marine animals and on ancient taxa such as conodonts, ammonoids, graptolites, and calcareous nanoplankton.

The boundaries between time units consistently formed intriguing clusters, they found, separated by lengthy spans of relative calm.

This uneven distribution suggests a multifractal system, or one whose complex dynamics are dictated by a continuous spectrum of exponents.

“The intervals between key events in Earth’s history, from mass extinctions to evolutionary explosions, are not scattered completely evenly,” Spiridonov says. “They follow a multifractal logic that reveals how variability cascades through time.”

The researchers sought to estimate Earth’s ‘outer time scale,’ or the amount of time needed to reveal the breadth of our planet’s natural variability.

Based on their findings, they conclude this span is at least 500 million years.

“If we want to understand the full range of Earth’s behaviours, whether periods of calm or sudden global upheaval, we need geological records that cover at least half a billion years. And ideally, a billion,” Spiridonov says.

Studying shorter time scales may fail to convey the extremes our planet is capable of producing, the researchers warn.

Since all of human history has occurred within just a recent sliver of tranquility, a more robust grasp of Earth’s large-scale patterns would likely be valuable.

To help characterize the distribution of these time units and their boundaries, the researchers developed a new model, which they describe as a “compound multifractal-Poisson process.”

Their analysis points to a structure of stage-defining events nested hierarchically, forming a cascade of clusters within clusters.

“We now have mathematical evidence that Earth system changes are not just irregular,” Spiridonov says. “They are deeply structured and hierarchical.”

Beyond helping us understand what has already happened on Earth over the past 4.5 billion years or so, these findings – along with future research building upon them – could offer invaluable insight about what to expect in the future.

“This has huge implications not only for understanding Earth’s past,” Spiridonov says, “but also for how we model future planetary change.”

The study was published in Earth and Planetary Science Letters.

Paleontologists have announced the discovery of a new genus and species of early eusauropod dinosaur from the Jurassic period of China.

Named Huashanosaurus qini, the new dinosaur species is estimated to have been around 12 m (39 feet) long.

It lived in what is now China’s Guangxi autonomous region from the Early to Middle Jurassic, 200 to 162 million years ago.

“Jurassic sauropods are well represented in China, especially in Yunnan, Sichuan, Chongqing and Xinjiang, with only a few localities known in Gansu, Ningxia, Anhui, Tibet and Guizhou,” said lead author Dr. Jinyou Mo from the Natural History Museum of Guangxi and colleagues.

“In Guangxi, the Jurassic record of dinosaur fossils is poor, compared with the Cretaceous dinosaur fossil record.”

Two specimens of Huashanosaurus qini — including a partial skeleton — were collected at Huqiu Quarry of the Wangmen Formation near Dongshi village in Guangxi, southern China.

Some bony fish scales and teeth (possibly Lepidotes sp.), several incomplete plesiosaurian teeth, and several fragmentary dinosaur bones were found at the site.

“The geological age of the Wangmen Formation is under debate,” the paleontologists said.

“It was originally regarded as early Early Jurassic, but paleontological evidence was lacking.”

“Scientists regarded it as the Early to Middle Jurassic based on the discovery of charophytes from this formation.”

According to the team, Huashanosaurus qini is a basal member of the Eusauropoda, a derived group of sauropod dinosaurs.

“It is the second eusauropod from Guangxi,” the researchers said.

“The first described eusauropod, Jingia dongxingensis, was excavated from the Late Jurassic Dongxing Formation.”

The discovery of Huashanosaurus qini provides additional information about the evolutionary radiation of eusauropod dinosaurs.

“Huashanosaurus qini is later-diverging than the Early Jurassic Vulcanodon, Tazoudasaurus, and Gongxianosaurus, as well as the Early to early Middle Jurassic Barapasaurus,” the scientists said.

“Generally, it is recognized that the major radiation of eusauropods occurred during the end of the Early Jurassic and Middle Jurassic interval.”

“From this point of view, the discovery of the eusauropod Huashanosaurus qini provides additional evidence for an Early to Middle Jurassic age for the Wangmen Formation.”

The findings were published in the journal Acta Geologica Sinica.

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Jinyou Mo et al. 2025. A New Eusauropod Dinosaur from the Lower and Middle Jurassic Wangmen Formation of Ningming County, Guangxi, South China. Acta Geologica Sinica 99 (4): 909-924; doi: 10.1111/1755-6724.15331

A recently discovered asteroid roughly the size of a commercial jet will pass within 1 lunar distance of Earth on Sept. 3. Here’s how you can watch the flyby live online, courtesy of the Virtual Telescope Project.

The near-Earth asteroid designated 2025 QD8 is expected to pass roughly 135,465 miles (218,009 kilometers) from our planet — roughly 57% the Earth-moon distance — at 10:57 a.m. ET (1456 GMT) on Sept. 3.

Fossils usually leave us with bones turned to stone, the hard remains of creatures long gone.

But every so often, nature offers something far rarer — a glimpse of soft tissue that survived for millions of years.

Researchers examining a 520-million-year-old arthropod larva were stunned to find not just an outline of the creature, but an interior anatomy preserved with extraordinary clarity.

The specimen, they said, represents one of the most detailed looks at early animal life ever recorded.

“It’s always interesting to see what’s inside a sample using 3D imaging,” Katherine Dobson, a co-author of the study said in the press release. “But in this incredible tiny larva, natural fossilization has achieved almost perfect preservation.”

That preservation included a surprising wealth of features.

Using synchrotron X-ray tomography, the team identified a brain, “digestive glands, a primitive circulatory system and even traces of the nerves supplying the larva’s simple legs and eyes,” according to the research announcement.

Such fine-grained detail, they said, revealed that these early arthropods were far more complex than previously assumed.

Martin Smith, the study’s lead researcher, said the find matched his most ambitious hopes.

“When I used to daydream about the one fossil I’d most like to discover, I’d always be thinking of an arthropod larva, because developmental data are just so central to understanding their evolution,” Smith said in the press release.

“But larvae are so tiny and fragile, the chances of finding one fossilized are practically zero — or so I thought!” Smith said.

The preserved brain contained a structure known as the protocerebrum, which researchers traced forward through evolutionary history into the distinctive head formations that have helped arthropods flourish in nearly every environment on Earth.

Smith described his reaction upon realizing what the fossil contained.

“I already knew that this simple worm-like fossil was something special, but when I saw the amazing structures preserved under its skin, my jaw just dropped — how could these intricate features have avoided decay and still be here to see half a billion years later?”

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Blind dates are exciting because they hold the potential for surprises, especially when dealing with an interstellar date partner of unknown origin.

On October 3, 2025, the interstellar object 3I/ATLAS will pass within a distance of 29 million kilometers from Mars. At that time, the HiRISE camera onboard the Mars Reconnaissance Orbiter will be able to image 3I/ATLAS with a resolution of 30 kilometers per pixel. The resulting closeup image might separate the contributions of the nucleus and surrounding dust cloud to the total luminosity of reflected sunlight stemming from 3I/ATLAS.

The Minimum Orbit Intersection Distance (MOID) of 3I/ATLAS from Mars, namely the closest distance that 3I/ATLAS gets to the complete path of Mars around the Sun, is merely 2.7 million kilometers. This by itself constitutes a remarkable fine-tuning of the path of 3I/ATLAS.

If 3I/ATLAS is a technological object, this short MOID makes it easy for a precursor mini-probe to reach Mars. In addition, an orbit correction by 10–15 kilometers per second during the month of September 2025, could shrink the closest approach distance of 3I/ATLAS from Mars to zero, as calculated in Figure 4 of my paper with Adam Hibberd and Adam Crowl (accessible here).

The ejection of icy fragments from the surface of a natural comet can only result in a velocity kick of order 0.4 kilometers per second based on the analysis of data from the Webb telescope (accessible here). This ejection speed is insufficient for these fragments to reach Mars. Moreover, the extent of the CO2 plume observed by SPHEREx around 3I/ATLAS (as reported here) is of order 350,000 kilometers, a distance beyond which the plume is expected to be confined by the ram-pressure from the solar wind. This distance is still shorter by a factor of a hundred from the value needed to reach Mars during the closest approach of 3I/ATLAS without a maneuver. Given all these considerations, the arrival of materials from 3I/ATLAS to Mars in October 2025 will be a potential signature of technology.

Gladly, the Labor Day holiday provided me with a relief from my routine administrative duties as director of Harvard’s Institute for Theory & Computation. In between interviews for television and podcasts, I calculated that if 3I/ATLAS has a precursor probe that was traveling ahead of it and sideways towards Mars by about 30 million kilometers, then this precursor probe would be able to intercept Mars on October 3, 2025 or during the week preceding it.

This provides a second motivation for using HiRISE within a month. In addition to imaging the nucleus and dust cloud of 3I/ATLAS, HiRISE could image Mars in search for any precursor objects that precede 3I/ATLAS and get closer to Mars than the main object. Near-Earth telescopes cannot detect the reflection of sunlight from precursor objects that are smaller than a hundred meters, the upper limit on the size of all space probes launched by humans so far.

Blind dates can be exciting if we observe the other side with curiosity and regard data collection as an opportunity to learn something new.

ABOUT THE AUTHOR

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Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.

Blue-colored food may soon come without the usual side of petroleum and instead with a side of algae.

In a major food technology breakthrough published in Food Hydrocolloids, Cornell University researchers have developed a heat- and light-stable blue dye from phycocyanin, a naturally occurring protein in algae, which offers a cleaner, safer alternative to synthetic dyes like Blue 1 and Blue 2.

The breakthrough targets a decades-old problem. Blue is one of the rarest pigments in nature, and its scarcity has kept food manufacturers reliant on artificial versions linked to health concerns, including hyperactivity in children and possible toxicity.

These dyes also come from dirty energy like oil and gas, contributing to the pollution of our air and water.

Phycocyanin, the same pigment that gives blue spirulina its electric hue, has been approved as a food colorant in the U.S. and other countries, but its instability under heat and light has limited its use. The Cornell team solved this by using a gentle chemical process to break the protein into smaller, uniform particles, retaining its striking blue color while boosting its ability to act as an emulsifier, protecting nutrients in oils and enhancing food texture.

Using advanced imaging tools like small-angle X-ray scattering, the scientists confirmed the protein’s nanoscale transformation was both stable and functional.

“It’s like using a magnifying glass to understand protein behavior,” said Alireza Abbaspourrad, the Yongkeun Joh associate professor of food chemistry and ingredient technology at Cornell. “Our goal is for phycocyanin to replace multiple synthetic items, colorant, emulsifier, and antioxidant, all in one.”

This breakthrough could help the food industry cut down on petroleum-based additives like Red dye 3, reduce chemical pollution, and deliver cleaner labels to consumers, all while giving chefs and food makers a natural blue color to work with. The research also aligns with growing consumer demand for plant-based, minimally processed ingredients and a move away from petroleum-based, overprocessed ones, which contribute to harmful pollution and extreme weather.

The research team, supported by the U.S. Department of Agriculture, is now working to scale up production with industry partners. If successful, this algae-powered pigment could hit grocery shelves within a few years, brightening foods and drinks while keeping harmful chemicals out of our bodies and the environment.

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