Category: 7. Science

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People who want to nobble renewable energy or anything else that maintains a liveable climate love to claim that old predictions have been wrong. “If climate scientists exaggerated how fast the world would warm years ago, why should we listen to them now?” the argument goes. However, these assertions rely on misrepresenting, or outright fabricating, what climate scientists were saying back in the day.

A team including Professor Torbjörn Törnqvist and Assistant Professor Sönke Dangendorf of Tulane University assessed the accuracy of climate models, not by looking at temperature changes, but by using sea level rise, which experiences smaller fluctuations.

“The ultimate test of climate projections is to compare them with what has played out since they were made, but this requires patience – it takes decades of observations,” Törnqvist said in a statement. 

Despite that more even trend, sea heights do move around, and we don’t just mean with tides and storms. Major flooding can move so much water from ocean to land that global sea levels drop, and when it happens on a flat continent like Australia, the effect can balance the ongoing rise for a surprisingly long time. There are also regional variations. When ocean currents speed up or slow down, water can bank up in some places and decline in others, so only a global view offers a true picture.

Nevertheless, satellite observations have shown a clear rising trend since we first had eyes in the sky that can measure the height of the oceans everywhere. Moreover, Törnqvist, Dangendorf, and co-authors found, the angle of the slope almost perfectly matches what was anticipated.

The pair used the 1996 Intergovernmental Panel on Climate Change (IPCC), which drew on the best models available at the time but was not influenced by satellite data, which was too new then to be useful.

That report projected a global average rise of 6-7 centimeters (2.4-2.8 inches) from 1993 to 2023 on the most likely scenario. The figure has turned out to be 8 cm (3.2 inches).

“We were quite amazed how good those early projections were, especially when you think about how crude the models were back then, compared to what is available now,” Törnqvist said. “For anyone who questions the role of humans in changing our climate, here is some of the best proof that we have understood for decades what is really happening, and that we can make credible projections.”

The small error comes almost entirely from the contribution of melting ice, primarily in Greenland and Antarctica. This has been almost 2 cm (about 1 inch), which is larger than the IPCC report expected. This is because the way warming waters can destabilize ice sheets where they meet the ocean, leading to faster flow, was not understood at the time.

Eight centimeters over 30 years may not sound too scary, but it is already creating havoc in some low-lying countries. Moreover, a consistent feature of models then and now is that the rise will not be linear; it will accelerate. Predictions for major cities to be regularly flooded at high tide are likely to be met right on schedule.

“Sea level doesn’t rise uniformly – it varies widely,” Dangendorf said. “Our recent study of this regional variability and the processes behind it relies heavily on data from NASA’s satellite missions and NOAA’s ocean monitoring programs. Continuing these efforts is more important than ever, and essential for informed decision-making to benefit the people living along the coast.”

The study is open access in Earth’s Future. 

Using scientific instruments in novel ways is a common practice, but still results in significant new discoveries. But sometimes, it doesn’t happen so much as a “that’s funny” moment as an intentional new use of old equipment. A new paper from researchers that Imperial College London (ICL), PhD student Solomon Hirsch and his advisor Mark Sephton, shows how the gas chromatograph-mass spectrometers that have been a mainstay of Martian probes since the Viking era could be used to find extant life there.

The formation of their idea is based around the presence of Intact polar lipids (IPLs), a type of organic biomarker that makes up the structural components of many cells, especially in single-celled lifeforms like bacteria and archaea. Typically, detection of these IPLs is done using solvent extraction of liquid chromatography methods, which are impractical for in-situ analysis on another planet, but the new paper shows how it can be done with pyrolysis-gas chromatography-mass spectrometry.

Before they could do any testing, though, the researchers had to decide what IPL signature they would look for in the data. IPLs degrade very quickly, which marks their presence as a distinct “viable life signature” since they only exist for a few hours or days after death, and degrade into other biomarkers post-mortem. Archaea and bacteria also use different IPLs in their structures, and as such would have different signatures both for their living ones and for their dead ones.

Fraser discusses the story of the search for life on Mars.

For living bacteria, the researchers chose 1,2-Dioleoyl-sn-glycero-3-phosphocoline, which in the lovely language of organic chemistry, is shortened to DOPC, and which degrades to oleic acid after the cell’s death. For archaea, the even longer organic chemistry name can be shortened to DPPE for the living IPL, with the post-mortem expected result called archaeol.

To test their theory, the researchers pyrolized (i.e. burned) samples of each of the four expected chemicals. The DOPC found in bacterial IPLs produced a distinct additional biomarker known as glyceryl monooleate, which wasn’t present when burning the degraded form of oleic acid. They also found they could use a reagent called hexamethyldisilazane to improve sensitivity of their finding, though its unclear how viable of an option that is for in-situ measurements.

Unfortunately, the distinction between living IPLs and their degradation product was much more difficult for archaea. While the test might prove useful in hinting at the presence of once extant life, it wouldn’t be as useful in determining whether it was actually still living or not.

Another fundamental assumption of the ICL research is that cells on Mars would use the same organic molecules as part of their strucutre. Fraser discusses how that might happen.

There are some additional challenges to overcome before this research can truly be implemented on other planets. Inorganic molecules commonly found on other planets, such as iron oxides and perchlorates (which are especially common on Mars) can obscure the signatures of these organic compounds. Additionally, there are more types of organic chemicals that make up IPLs here on Earth than were studied in this first research paper – so not finding evidence of the specific type of IPLs found in these certain types of bacteria does not necessarily mean there weren’t other types present.

But ultimately what the study authors suggest is to use this tool as a first screener in situ for a preliminary peek at whether or not life might be present in a collected sample. Those samples could be collected anywhere from the sub-surface of Mars to the geysers on Enceladus, but they would still have the same signature. Given that the work can be done with a tried and true flight tested system which has been in use for decades, there’s really no harm in looking for these signatures as part of the standard suite of tests on future missions – and if researchers happen to find a tell-tale sign of organic molecules or not, that’s one other data point in the long story of our search for life in the universe.

Learn More:

Simon Levey, ICL/Phys.org – Signs of recent life on Mars could be detected using new simple test

Solomon Hirsch & Mark A. Sephton – Intact polar lipids as organic biomarkers of viable extraterrestrial life

UT – A Simple Instrument Could Find Martian DNA – If It Exists

UT – Long-chain Hydrocarbons Found on Mars

A diverse array of objects exists in space, ranging in size from tiny dust particles to supermassive black holes. However, much of what astronomers study is groupings of these objects bound together by gravity. At the small end of these groupings are planets and their moons, referred to as systems. Then there are stars and their planets, known as planetary systems. Finally, there are stars, black holes, and the gas and dust between them, which are galaxies. Beyond that, groupings of objects so huge that they form larger patterns in the whole universe are called structures. A type of structure composed of hundreds to thousands of galaxies is known as a galaxy cluster.

Astronomers want to know how being part of a larger structure, like a galaxy cluster, affects all the objects in it, especially as the structure takes shape over time. One team studied what happened to galaxies as they fell into the Abell 496 cluster. The cluster’s mass is about 400 trillion times that of the Sun, and it is relatively nearby for a galaxy cluster at 140 megaparsecs, 4 sextillion kilometers, or 3 sextillion miles from the Earth. 

They wanted to know how the galaxies evolved after they fell into the cluster. So they observed 22 galaxies inside Abell 496 to see if they could find any differences in how they formed stars as they fell farther into it. In particular, they aimed to pinpoint the moment in time over the last billion years when regular star-forming galaxies in this cluster ceased to create new stars.

The team combined 2 distinct pieces of data about the light coming from the galaxies they observed in the cluster. The first was long-wavelength emissions coming from neutral hydrogen atoms in the dust between the galaxy’s stars, known as HI and pronounced “H one.” They interpreted patterns in these HI emissions to find how much a galaxy has been disturbed by its proximity to other galaxies, and how much gas it has left to form stars. The team observed the HI emissions from these galaxies using the National Radio Astronomy Observatory’s Very Large Array. 

The second piece of data they used consisted of short-wavelength far-ultraviolet emissions emanating from newly formed stars with masses between 2 and 5 times that of the Sun. These stars are short-lived with lifespans shorter than 1 billion years. Researchers use the emission patterns in these far-ultraviolet measurements to calculate the frequency at which stars form in galaxies. The team made these observations with the Ultra-Violet Imaging Telescope on the AstroSat satellite.

The team combined these data to unravel the history of each galaxy, including when their stars formed, when they started being affected by other galaxies, and how long their reserves of star-making gas lasted. Then, they used each galaxy’s position in the cluster and its trajectory to determine how the process of falling into the cluster had altered its evolutionary path. 

They found that galaxies near the edge of the cluster formed stars at a rate they would consider undisturbed or main-sequence. They also found that over half of the 22 galaxies they studied were located at the center of the cluster, firmly bound together by gravity and subject to its secondary effects. However, of those galaxies, none had reached the part of their orbits where they pass closest to the exact center of the cluster, since they had only been falling into the cluster for the last few 100 million years.

The researchers used their data to develop a 5-step evolutionary sequence for galaxies that fall into a cluster. First, the galaxies begin to fall into a cluster and undergo default, main-sequence star formation, referred to as pre-triggering. Second, other galaxies in the cluster disrupt the falling galaxies’ HI, sharply increasing how frequently they form stars, referred to as initial star formation triggering. 

Third, the galaxies’ HI is highly disturbed, and they form stars at their highest level, referred to as the peak of star formation. Fourth, their HI remains very disrupted, but far-ultraviolet emissions from star formation drop, referred to as their star formation fading. They estimated that these first 4 steps together would take a few 100 million years. Fifth, the galaxies’ HI is depleted, and star formation drops to levels below those of the pre-disturbance main sequence, referred to as quenching.

The team concluded that their method reconstructed a reasonable history of a galactic cluster. However, they suggested future teams should ensure that they have accurate methods for measuring both star formation and neutral gas in distant galaxies. They recommended that these teams use larger numbers of galaxies in clusters for more accurate statistical analyses and study multiple clusters with different local environments to better understand how galaxies evolve within larger structures.

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Newswise — COLUMBUS, Ohio – Stars die and vanish from sight all the time, but astronomers were puzzled when one that had been stable for more than a decade almost disappeared for eight months. 

Between late 2024 and early 2025, one star in our galaxy, dubbed ASASSN-24fw, dimmed in brightness by about 97%, before brightening again. Since then, scientists have been swapping theories about what was behind this rare, exciting event. 

Now, an international team led by scientists at The Ohio State University may have come up with an answer to the mystery. In a new study recently published in The Open Journal of Astrophysics, astronomers suggest that because the color of the star’s light remained unchanged during its dimming, the event wasn’t caused by the star evolving in some way, but by a large cloud of dust and gas around the star that occluded Earth’s view of it. 

“We explored three different scenarios for what could be going on,” said Raquel Forés-Toribio, lead author of the study and a postdoctoral researcher in astronomy at Ohio State. “Evidence suggests it is likely that there is a cloud of dust in the form of a disk around it.”

ASASSN-24fw is an F-type star — a star that is a little more massive than our sun and about twice as big —  and is located about 3,000 light-years away from Earth. Researchers estimate that the cloudy disk it’s surrounded by is about 1.3 astronomical units (AU) across, even bigger than the distance between the sun and our planet. (One AU is the distance between the center of the Earth and the center of the sun.)

Researchers suggest this disk is also likely made up of large clusters of carbon or water ice close in size to a large grain of dust found on Earth. This material is similar enough to planet-forming disks that studying it could give astronomers novel insights into stellar formation and evolution. 

Yet these findings alone don’t explain all of the system’s abnormalities, said Forés-Toribio. Instead, researchers think that a smaller, cooler star may also orbit ASASSN-24fw, which would make it a hidden binary system.  

“At this moment, with the data that we have, what we propose is that there should be two stars together in a binary system,” said Forés-Toribio. “The second star, which is much fainter and less massive, may be driving the changes in geometry leading to the eclipses.” 

While dimming systems like the one the team saw are rare, this one-in-a-million eclipsing was especially dramatic, said Chris Kochanek, co-author of the study and a professor of astronomy at Ohio State, as even when researchers searched for similar objects, they couldn’t find one that fit the same exact pattern. 

“We were hoping to find some similarities and we didn’t really find very many, which is interesting in and of itself,” said Kochanek. “But the hope is, as we find more in the future, some patterns might eventually be revealed.” 

The system was discovered as part of the All-Sky Automated Survey for Supernovae (ASAS-SN) project, a network of small telescopes that monitor the entire visible night sky. Since its establishment more than a decade ago, ASAS-SN has collected about 14 million images and counting of the cosmos. 

“The universe’s capacity to surprise us is continuous,” said Krzysztof Stanek, another co-author of the study and a professor of astronomy at Ohio State. “Even with small telescopes on the ground and big telescopes in space, every time we get a new capability, we still discover new things.”

According to the team, the ASASSN-24fw system likely experiences an eclipse about once every 43.8 years, with the next one not expected to occur until around 2068. While some members of the team don’t expect to be around to study that event, they hope that the work they leave in cultivating these long-term sky surveys gives future scientists a foundation to make all sorts of new, exciting discoveries. 

“We want our data to be accessible a hundred years from now, even if we are not around,” said Stanek. “The main point of ASAS-SN is, if something happens in the sky, we’ll have historical data for it.”

In the meantime, the team wants to make use of larger telescopes like The James Webb Space Telescope and the ground-based Large Binocular Telescope Observatory to make more complete observations of the system as it returns to full brightness.  

“This study is a particularly interesting example of a broader class of still very strange objects,” said Stanek. “We learn more about astrophysics when we find things that are unusual, because it pushes our theories to the test.”

Other Ohio State co-authors include Brayden JoHantgen, Michael Tucker, Lucy Lu and Dominick Rowan, as well as scientists at Boston University, University of Hawai’i, Carnegie Observatories, University of Vienna, Florida State University, The University of Melbourne, University of California, Santa Cruz and Ball State University.

This work was supported by the National Science Foundation and NASA, the Gordon and Betty Moore Foundation and the Alfred P. Sloan Foundation.

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Contact: Raquel Forés-Toribio, [email protected]

Written by: Tatyana Woodall, [email protected]

A dramatic and unusually long total lunar eclipse will light up the skies above the UAE on the night of September 7, 2025, turning the Moon a deep red during an 82-minute totality — one of the longest such events in recent years. The eclipse, visible across much of the globe, will offer residents and global viewers a rare chance to witness a breathtaking astronomical display, with public events and global livestreams planned.

On September 7, 2025, the UAE will experience a total lunar eclipse, an event in which the Earth positions itself precisely between the Sun and the Moon, casting its shadow fully across the lunar surface. This alignment causes the Moon to turn a red, copper, or orange hue — a phenomenon popularly known as the Blood Moon.This reddish color results from sunlight being refracted through Earth’s atmosphere, which filters out shorter blue wavelengths and allows the longer red tones to reach the Moon’s surface.What makes this eclipse especially notable is the length of totality, lasting a full 82 minutes, and the overall eclipse duration of nearly five and a half hours, one of the longest in recent memory. According to the Dubai Astronomy Group (DAG), the event is not only rare for its duration but also for its global visibility, potentially viewable by 87% of the world’s population.

The lunar eclipse will unfold gradually through several distinct phases. Each stage offers a different visual experience, and residents in the UAE will be able to observe the entire sequence clearly:

The most visually dramatic moment, totality, will occur between 9:30 PM and 10:53 PM, when the Moon is fully engulfed in Earth’s umbra and glows with intense red shades depending on atmospheric conditions.

Where and how to watch in the UAE and beyond

For the public, the Dubai Astronomy Group will organize a special viewing event in Dubai, allowing residents and tourists to gather and witness the phenomenon together. Details about the event venue and activities are expected to be announced soon. A standout moment will be a carefully planned photo opportunity: a Blood Moon rising behind the Burj Khalifa, captured in collaboration with renowned photographer Rami Dibo.To ensure global accessibility, DAG will also host a livestream of the full eclipse. The broadcast will feature:

This global streaming effort aims to bring together astronomy enthusiasts worldwide for a shared celestial experience.

Viewing tips and future eclipses

Safe viewingUnlike solar eclipses, lunar eclipses are safe to view with the naked eye — no protective glasses or filters are needed. However, for those wanting an enhanced viewing experience, DAG recommends the following:

For photography enthusiasts

What’s next?If you miss this eclipse, there are a few more chances in the coming years:

algae: Single-celled organisms, once considered plants (they aren’t). As aquatic organisms, they grow in water. Like green plants, they depend on sunlight to make their food.

base pair: (in genetics) (in genetics) Two nucleotides pair up to form each rung in DNA’s or RNA’s ladder-like structure. In DNA, each nucleotide contains a base — either adenine (A), cytosine (C), guanine (G) or thymine (T) — together with a phosphate group and a sugar molecule (deoxyribose). In RNA, the bases are A, C, G and uracil, or U (and the nucleotide’s sugar is ribose). Bases link into pairs. And they’re picky. In DNA, A only pairs with T; G only pairs with C. In RNA, A always pairs with U and G only pairs with C. Base pair may also be a term for how many of these combos make up a particular string of nucleotides (such as one might be described as 8 base pairs long).

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

chromosome: A single threadlike piece of coiled DNA found in a cell’s nucleus. A chromosome is generally X-shaped in animals and plants. Some segments of DNA in a chromosome are genes. Other segments of DNA in a chromosome are landing pads for proteins. The function of other segments of DNA in chromosomes is still not fully understood by scientists.

deletion: (v. to delete) The process of removing some specific part or detail; or a reference to the things that has been removed.

DNA: (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. It is built on a backbone of phosphorus, oxygen, and carbon atoms. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

egg: A reproductive cell that contains half of the genetic information necessary to form a complete organism. In humans and in many other animals, ovaries produce eggs. When an egg fuses with a sperm, they combine to produce a new cell, called a zygote. This is the first step in the development of a new organism.”

function: The specific role some structure or device plays.

gene: (adj. genetic) A segment of DNA that codes, or holds instructions, for a cell’s production of a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.

genetic: Having to do with chromosomes, DNA and the genes contained within DNA. The field of science dealing with these biological instructions is known as genetics. People who work in this field are geneticists.

genome: The complete set of genes or genetic material in a cell or an organism. The study of this genetic inheritance housed within cells is known as genomics.

molecule: A group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in air is made of two bound oxygen atoms (O₂). Water is made of two hydrogen atoms and one oxygen atom (H₂O).

organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.

protein: A compound made from one or more long chains of amino acids. Proteins are an essential part of all living organisms. They form the basis of living cells, muscle and tissues; they also do the work inside of cells. Antibodies, hemoglobin and enzymes are all examples of proteins. Medicines frequently work by latching onto proteins.

red blood cell: Colored red by hemoglobin, these cells move oxygen from the lungs to all tissues of the body. Red blood cells are too small to be seen by the unaided eye.

species: A group of similar organisms capable of producing offspring that can survive and reproduce.

sperm: A reproductive cell that contains half of the genetic information necessary to form a complete organism. In humans and in many other animals, testes produce sperm. When a sperm fuses with an egg, the two combine to produce a new cell, called a zygote. This is the first step in the development of a new organism.”

virus: Tiny infectious particles consisting of genetic material (RNA or DNA) surrounded by protein. Viruses can reproduce only by injecting their genetic material into the cells of living creatures. Although scientists frequently refer to viruses as alive or dead, in fact many scientists agree that viruses are not truly alive. They don’t eat as animals do or make their own food as plants do. A virus must hijack the cellular machinery of a living cell to survive.