This is an excerpt from the above-titled article in Live Science. I highly recommend clicking through to read the whole thing!
Females have one active X chromosome and one dormant X chromosome in each cell. But a study suggests that genes on the dormant X get "reawakened" later in life, potentially giving the brain a boost.
Dormant genes on the X chromosome may reawaken in old age, potentially giving the aging female brain a boost that the male brain doesn't receive. This phenomenon may help to explain why, on many measures, females show a higher level of cognitive resilience in old age than males do.
Males typically carry one X and one Y in each cell; they inherit the X from their mother and the Y from their father. Females, on the other hand, usually carry two X chromosomes — one from mom and one from dad. But each cell needs only one X to be active, so in females, the second X is "silenced," leaving only the maternal or paternal X switched on.
Among the 22 reawakened genes, one called PLP1 carries the instructions to make a key component of myelin, the fatty insulation that helps neurons send signals efficiently. It's known that mutations in PLP1 can decrease the amount of myelin in the brain, resulting in intellectual disability. It's also known that myelin can be compromised in aging and that loss of myelin function can contribute to cognitive decline.
To see if the reawakening of PLP1 might boost cognition, scientists confirmed that older female mice had more PLP1 activity in their hippocampi than the older male mice did. They artificially increased PLP1 using gene editing in both old males and old femalesfound that both sexes performed better on tests of learning and memory after that boost.
To see if any of the findings extended to humans, the team looked at data previously collected for a large study of human brain tissue. Data weren't available for the hippocampus, but the brain tissue immediately surrounding the hippocampus showed more PLP1 activation in older women than in older men. So that hints that the same phenomenon might be unfolding in people.
A team of engineers and geophysicists led by the University of Chicago proposed a new method for terraforming Mars with nanoparticles. This method would take advantage of resources already present on the Martian surface and, according to their feasibility study, would be enough to start the terraforming process.
When neutron stars dance together, the grand smash finale they experience might create the densest known form of matter known in the Universe. It’s called “quark matter, ” a highly weird combo of liberated quarks and gluons. It’s unclear if the stuff existed in their cores before the end of their dance. However, in the wild aftermath a neutron-star merger, the strange conditions could free quarks and gluons from protons and neutrons. That lets them move around freely in the aftermath. So, researchers want to know how freely they move and what conditions might impede their motion (or flow).
Recently, two researchers looked at what would happen if a ship with warp drive tried to get into a black hole. The result is an interesting thought experiment. It might not lead to starship-sized warp drives but might allow scientists to create smaller versions someday.
Gender reveal parties are best known as celebrations involving pink and blue, cake and confetti, and the occasional wildfire. Along with being social media hits, gender reveals are a testament to how society is squeezing children into one of two predetermined gender boxes before they are even born.
These parties are often based on the 18- to 20-week ultrasound, otherwise known as the anatomy scan. This is the point during fetal development when the genitals are typically observed and the word “boy” or “girl” can be secretly written on a piece of paper and placed into an envelope for the planned reveal.
Now there is a new player in the gender reveal game: genetic screening.
Advancements in genetic research have led to the development of a simple blood test called cell-free DNA prenatal screening that screens for whether a baby has extra or missing pieces of genetic information – chromosomes – as early as 10 weeks into pregnancy. Included in this test are the sex chromosomes, otherwise known as X and Y, that play a role in the development and function of the body.
This blood test is more informally called noninvasive prenatal testing, or NIPT. Many people refer to it as “the gender test.” But this blood test cannot determine gender.
As genetic counselors and clinical researchers working to improve genetic services for gender-diverse and intersex people, we emphasize the significance of using precise and accurate language when discussing genetic testing. This is critical for providing affirming counseling to any patient seeking pregnancy-related genetic testing and resisting the erasure of transgender and intersex people in health care.
Distinguishing sex and sex chromosomes
Sex and gender are often used interchangeably, but they represent entirely different concepts.
Typically when people think of sex, they think of the categories female or male. Most commonly, sex is assigned by health care providers at birth based on the genitals they observe on the newborn. Sex may also be assigned based on the X and Y chromosomes found on a genetic test. Commonly, people with XX chromosomes are assigned female at birth, and people with XY chromosomes are assigned male. Since cell-free DNA, or cfDNA, prenatal screening can report on sex chromosomes months before birth, babies are receiving sex assignments much sooner than previously possible.
While cfDNA prenatal screening can offer insights into what sex chromosomes an infant may have, sex determination is much more complicated than just X’s and Y’s.
For one, sex chromosomes don’t exactly determine someone’s sex. Other chromosomes, hormone receptors, neural pathways, reproductive organs and environmental factors contribute to sex determination as well, not unlike an orchestra with its ensemble of instruments. Each cello, flute, tympani and violin plays a crucial role in the performance of the final musical score. There is no single instrument that defines the entirety of the symphony.
Expanding social and medical concepts of sex and gender beyond the binary can help patients and doctors.
Intersex people, or those with variations in sex characteristics that deviate from societal norms of binary sex, exemplify the complexities of sex. These variations can manifest in various ways beyond X and Y chromosomes, such as differences in hormone levels, genitalia or secondary sexual characteristics.
The oversimplification of sex based on societal norms has led many to believe that there are only two discrete sexes. The binary framework of sex excludes intersex people and perpetuates their erasure and mistreatment within both health care and society at large.
While sex typically describes someone’s anatomical characteristics, gender is an umbrella term that encompasses the way someone views and presents themselves to the world. Countless aspects influence how someone defines their own gender and how the world views their gender, including clothing, haircuts and voice tone. Similar to how Western cultures have historically confined sex to two buckets, it has also created two gender categories: man and woman.
Gender is not dependent on anatomical parts or chromosomes. People are not math equations, and having certain combinations of biological parts does not equal someone’s gender. For example, some people may be transgender, meaning their assigned sex is not congruent with their socially or self-defined gender. Nonbinary people do not identify exclusively with either of the two genders in the binary, regardless of their assigned sex.
Just like sex diversity, gender diversity is not rare. A 2022 Pew Research Center analysis found that approximately 5% of adults in the U.S. under the age of 30 are transgender or nonbinary.
Intersex and gender-diverse people show that sex and gender are both multidimensional. Gender is not solely determined by biology, and it is erroneous to define someone’s gender by their sex, much less by their sex chromosomes.
For instance, societal norms dictate that women should be nurturing and gentle, while men are expected to be protective and assertive. Such rigid gender roles, often enforced through the lens of biology, serve to uphold notions of evolutionary destiny and a purported natural order.
Marketing strategies for children’s toys often adhere strictly to gender roles, steering girls toward dolls and domestic play sets while steering boys toward action figures and construction sets.
Educational systems often reinforce gender norms by directing girls toward subjects such as literature and arts while steering boys toward science and mathematics. This perpetuates the notion that certain traits and interests are inherently linked to one’s sex and gender, thereby reinforcing societal norms and sustaining inequality.
Upholding binary constructs of sex and gender does not allow for individuality and gender fluidity. Categorizing people from the time their chromosomes are analyzed or the moment their genitals are observed at birth restricts their autonomy and authenticity. These simple assumptions set expectations that can be harmful.
Letting children define themselves
If you’re a parent offered cfDNA prenatal screening during pregnancy, remember that it is commenting only on one instrument in the orchestra of sex. It cannot examine all of the other factors that determine sex as a whole. And it most certainly cannot determine gender, which is an entirely different concert.
In recent years, Jenna Karvunidis, the mother considered the inventor of gender reveal parties, shared her regrets for starting the trend and noted that her views on sex and gender have shifted. In a 2019 Facebook post, Karvunidis wrote, “PLOT TWIST. The world’s first gender reveal party baby is a girl who wears suits!” She had also gone on to say, “Celebrate the baby … Let’s just have a cake.”
When the envelope is opened, the balloons are popped and the crafty cake is cut, consider how these practices perpetuate social confinements and a gendered destiny for your little bundle of joy. Perhaps opt simply for a celebration that leaves space for your child to one day define who they are.
Using the European Space Agency's (ESA) ExoMars Trace Gas Orbiter (TGO), scientists have observed Mars' atmosphere glowing green for the first time ever — in the visible light spectrum, that is. The effect is called airglow (or dayglow or nightglow, depending on the hour). Nightglow "occurs when two oxygen atoms combine to form an oxygen molecule," according to ESA. On Mars, this happens at an altitude of approximately 31 miles (50 km). Scientists have suspected Mars to have airglow for some 40 years, but the first observation only occurred a decade ago by ESA's Mars Express orbiter, which detected the phenomenon in the infrared spectrum. Then, in 2020, scientists observed the phenomenon in visible light using TGO, but in Martian daylight rather than at night. Now, we've seen the phenomenon at night via TGO.
The moon is at least 40 million years older than we once thought, a new study reveals. Scientists confirmed our cosmic companion's new minimum age after reanalyzing tiny impact crystals from lunar samples taken by NASA's Apollo 17 mission in 1972. Earth is approximately 4.54 billion years old. So based on the newest study, the zircon crystals were formed around 80 million years after our planet formed. However, the collision that birthed the moon could have actually happened even earlier. After the Earth-Thea crash, the infant moon's surface would have been covered by a magma ocean due to the intense energy of the collision. Therefore, the lunar zircon crystals could only have properly solidified into their current state once the magma ocean had cooled down.
Astrobiologists think a planet needs to have certain features to support life: oxygen in its atmosphere, something to shield organisms from dangerous radiation and liquid water, for a start. Although big land masses aren't strictly necessary for living things to emerge, Earth's history shows that they're important for life to thrive and exist for long periods of time. So, if an exoplanet had continents before Earth, it follows that there might be older, more advanced life on that world.
This line of thought led Jane Greaves, an astronomer at Cardiff University astronomer in the U.K., to answer the question: When did the first continents appear on a planet in our galaxy? Turns out, two exoplanets' continents — and perhaps life — may have arisen four to five billion years before Earth's.
If the Tasmanian Devil is a type of dead star, it’s not behaving like the others. As a dead star, the light coming from it could signal its transition into a sort of stellar afterlife. It could be a new type of stellar corpse. “Because the corpse is not just sitting there, it’s active and doing things that we can detect,” Ho said. “We think these flares could be coming from one of these newly formed corpses, which gives us a way to study their properties when they’ve just been formed.”
In the very early universe, physics was weird. A process known as “inflation,” where best we understand the universe went from a single infinitesimal point to everything we see today, was one such instance of that weird physics. Now, scientists from the Chinese Academy of Science have sifted through 15 years of pulsar timing data in order to put some constraints on what that physics looks like.
When methane (CH4) and oxygen (O2) are both present in an atmosphere, it’s an indication that life is at work. That’s because, in an oxygen environment, methane only lasts about 10 years. Its presence indicates disequilibrium. For it to be present, it has to be continually replenished in amounts that only life can produce.
This aging and still-valuable spacecraft has been exploring the outer parts of the solar system since its launch in 1977, along with its twin sibling, Voyager 2. They each traveled slightly different trajectories. Both went past Jupiter and Saturn, but Voyager 2 continued on to Uranus and Neptune. They’re both now outside the solar system, sending back data about the regions of space they’re exploring.
Voyager 1 flew past Jupiter in March 1979, and Saturn in November 1980. After its close approaches to those two gas giants, it started a trajectory out of the solar system and entered interstellar space in 2013. That’s when it ceased to detect the solar wind and scientists began to see an increase in particles consistent with those in interstellar space.
These days, Voyager 1 is more than 157.3 astronomical units from Earth and moving out at well over 61,000 km/hour. It’s busy collecting data about the interstellar medium and radiation from distant objects. If all goes well, the spacecraft should continue sending back data for nearly a decade. After that, it should fall silent as it travels beyond the Oort Cloud and out to the stars.
Earlier this year, however, the teams attached to the Voyager 1 mission noticed that the spacecraft was sending weird readouts about its attitude articulation and control system (called AACS, for short). Essentially, the AACS was sending telemetry data all right, but it was routing it to the wrong computer, one that had failed years ago. This corrupted the data, which led to the strangely garbled messages the ground-based crew received.
Once the engineers figured out that the old, dead computer might have been part of the problem, they had a way forward. They simply told the AACS to switch over sending to the correct computer system. The good news was that it didn’t affect science data-gathering and transmission. The best news came this week: team engineers have fixed the issue with the AACS and the data are flowing normally again.
The ongoing issue with AACS didn’t set off any fault protection systems onboard the spacecraft. If it had, Voyager 1 would have gone into “safe mode” while engineers tried to figure out what happened. During the period of garbled signals, AACS continued working, which indicated that the problem was either upstream or downstream of the unit. The fact that data were garbled provided a good clue to related computer issues.
This adapted article appeared in Universe Today. Click through for the full thing.
Science news articles abound, everything from the results of carefully designed peer-reviewed research studies to fear-based rumors and anti-science biased conspiracy theories. How are we to discern which are reliable, which are hype based on misinterpretation, flawed studies, and the like, and which are clickbait nonsense?
The first thing I do is look at the source. Mediabiasfactcheck and other sites provide information as to the right-left biases and factual accuracy of a given source, although not of a particular story. Science Based Medicine is also helpful. I've been known to search under "Is Dr. So-and-So a quack?" and get useful answers.
I also check my own reactions: Is this too good to be true? Is it at odds with what I understand about science (my academic background is biology and health sciences)? Have I seen an article in a trusted source (such as the newsletter from Center for Science in the Public Interest) debunking this or similar claims? I've been also known to check with friends with special expertise in the field.
The Conversation offers some guidelines on assessing the quackery scale of science new stories. Their suggestions:
1. Has the story undergone peer review?
Scientists rely on journal papers to share their scientific results. They let the world see what research has been done, and how.
Once researchers are confident of their results, they write up a manuscript and send it to a journal. Editors forward the submitted manuscripts to at least two external referees who have expertise in the topic. These reviewers can suggest the manuscript be rejected, published as is, or sent back to the scientists for more experiments. That process is called “peer review.”
Research published in peer-reviewed journals has undergone rigorous quality control by experts. Each year, about 2,800 peer-reviewed journals publish roughly 1.8 million scientific papers. The body of scientific knowledge is constantly evolving and updating, but you can trust that the science these journals describe is sound. Retraction policies help correct the record if mistakes are discovered post-publication.
Peer review takes months. To get the word out faster, scientists sometimes post research papers on what’s called a preprint server. These often have “RXiv” – pronounced “archive” – in their name: MedRXiv, BioRXiv and so on. These articles have not been peer-reviewed and so arenot validated by other scientists. Preprints provide an opportunity for other scientists to evaluate and use the research as building blocks in their own work sooner.
How long has this work been on the preprint server? If it’s been months and it hasn’t yet been published in the peer-reviewed literature, be very skeptical. Are the scientists who submitted the preprint from a reputable institution? During the COVID-19 crisis, with researchers scrambling to understand a dangerous new virus and rushing to develop lifesaving treatments, preprint servers have been littered with immature and unproven science. Fastidious research standards have been sacrificed for speed.
A last warning: Be on the alert for research published in what are called predatory journals. They don’t peer-review manuscripts, and they charge authors a fee to publish. Papers from any of the thousands of known predatory journals should be treated with strong skepticism.
2. Be aware of your own biases.
Beware of biases in your own thinking that might predispose you to fall for a particular piece of fake science news.
There's a lot of very cool immunology research being done right now in response to the COVID-19 pandemic. Anti-virals and vaccines top the list for many. But there are significant problems with each -- anti-virals have not proven to be wonder drugs, offering only modest help for those already seriously ill, and an effective vaccine is still months or years away. Vaccines may have to be tailored to the age and immune status of various groups, just the way flu vaccines are. But there are other ways of thinking about minimizing both mortality (deaths) and morbidity (illnesses).
This is from Nevan Krogan, Professor and Director of Quantitative Biosciences Institute & Senior Investigator at the Gladstone Institutes, University of California, San Francisco
Kinases are proteins found in every cell of our body. There are 518 human kinases, and they act as major control hubs for virtually all processes in the body. They are able to add a small marker – a process called phosphorylation – to other proteins and thus change how, if and when a phosphorylated protein can do its work. Many cancers are caused by overactive kinases leading to uncontrolled cell growth, and drugs that slow kinases down can be highly effective at treating cancer.
Kinases are also fairly easy to target with drugs because of how they add phosphorylation markers to proteins. Researchers have developed a huge number of drugs, particularly cancer drugs, that work by essentially throwing a wrench into the mechanics of specific kinases in order to stop cell growth.
Viruses also change the function of cellular machinery – albeit on purpose – but instead of causing cell growth, the machinery is repurposed to produce more viruses. Not surprisingly, viruses take control over many kinases to do this.
It is impossible to actually see which kinases are activated at any time, but since each kinase canattach phosphorylation markers to only a few specific proteins, researchers can look at the phosphorylated proteins to determine what kinases are active at any time.
Some of the more interesting ones include Casein Kinase 2, which is involved in controlling how a cell is shaped. We also identified several kinases that work together in what is called the p38/MAPK signaling pathway. This pathway responds to and controls our body’s inflammation reaction. It is possible these kinases could be involved in the cytokine storm – a dangerous immune system overreaction – that some patients with severe COVID-19 experience.
While identifying the kinases involved in SARS-CoV-2 replication, we were also able to learn a lot about how the virus changes our bodies. For example, CK2 becomes much more active during the course of coronavirus infection and causes the growth of little tubes that extend from the surface of the cell. Under a microscope, it looks as if the cell has a full head of hair. We think SARS-CoV-2 might be using these long cell outgrowths – called filopodia – as viral highways to get new viruses closer to neighboring cells, thereby making infection easier.
There are 87 existing drugs that change the kinase-controlled pathways used by the coronavirus. Most of these drugs are already approved for human use or are currently in clinical trials to treat cancer, and could be quickly repurposed to treat COVID-19 patients.*
Liangfang Zhang, Professor of Nanoengineering, University of California San Diego describes another approach, playing defense instead of offense with the virus, as it were*
We create decoys that look like the human cells the SARS-CoV-2 virus invades. So far, we’ve made lung-cell decoys and immune-cell decoys. These cell decoys attract and neutralize the SARS-CoV-2 virus, leaving the real lung or immune cells healthy.
In 2019, scientists witnessed a massive star 2.5 million times brighter than the sun disappear without a trace. Now, in a new paper published today (June 30) in the journal Monthly Notices of the Royal Astronomical Society, a team of space detectives (see: astrophysicists) attempt to solve the case of the disappearing star by providing several possible explanations. Of these, one twist ending stands out: Perhaps, the researchers wrote, the massive star died and collapsed into a black hole without undergoing a supernova explosion first — a truly "unprecedented" act of stellar suicide.
This suggests that even short training programs of 6–12 months are enough to positively influence the health of people suffering from metabolic disorders," says last author Carl Johan Sundberg, professor at the Department of Physiology and Pharmacology, Karolinska Institutet. "The study identifies important 'exercise-responsive' genes that may play a role in metabolic diseases.
The red cloth-wrapped leather bootie, now part of the State Hermitage Museum's collection, is a stunner, trimmed in tin, pyrite crystals, gold foil and glass beads secured with sinew. Fanciful shapes—ducklings, maybe?—decorate the seams. But the true mind-blower is the remarkable condition of its sole. The British Museum curators’ explanation is that Scythians seated themselves on the ground around a communal fire, subjecting their soles to their neighbors’ scrutiny.
Peculiar flat regions on Saturn’s moon Titan could be the dry floors of ancient lakes and seas. The suggestion, published June 16 in Nature Communications, may solve a 20-year-old mystery.
The researchers considered whether rainfall, dunes or dry lake beds could be responsible for the reflections, and found that only lake beds explain the timing and locations of the signals. It does rain on Titan, but not frequently enough to explain the reflections, and Titan’s dune fields are in the wrong spots. And the specular reflections come from two specific regions that look like other empty lake basins near Titan’s poles (SN: 4/15/19).
Scientists have found evidence of plate tectonics on Jupiter’s moon Europa. This conceptual illustration of the subduction process (where one plate is forced under another) shows how a cold, brittle, outer portion of Europa’s 20-30 kilometer-thick (roughly 10-20 mile) ice shell moved into the warmer shell interior and was ultimately subsumed. A low-relief subsumption band was created at the surface in the overriding plate, alongside which cryolavas may have erupted. Image credit: Noah Kroese, I.NK
More evidence came from studying the brown splotches on Europa’s surface. Scientists hypothesized that those are chemicals from the subsurface ocean which have made their way to the surface. This shows that the sea floor might be interacting with the surface, an important consideration when thinking about habitability.
The discovery of liquid plumes raised the excitement level about Europa’s potential habitability.
For the little brown bat -- a small mouse-eared bat with glossy brown fur -- a warm, dry place to roost is essential to the species' survival. Reproductive females huddle their small furry bodies together to save thermal energy during maternity season (summer), forming "maternity colonies." In the face of severe population losses across North America, summer access to an attic or other permanent sheltered structure, as opposed to just trees or rock crevices, is a huge benefit to these bats.
[Bat image: By SMBishop - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=53580349]
The upper galaxy is labelled UGC 1810 by itself, but together with its collisional partners is known as Arp 273. The overall shape of the UGC 1810 -- in particular its blue outer ring -- is likely a result of wild and violentgravitationalinteractions. The blue color of the outer ring at the top is caused by massive stars that are blue hot and have formed only in the past few million years. The inner part of the upper galaxy -- itself an older spiral galaxy -- appears redder and threaded with cool filamentary dust. A few bright stars appear well in the foreground, unrelated to colliding galaxies, while several far-distant galaxies are visible in the background. Arp 273 lies about 300 million light years away toward the constellation of Andromeda. Quite likely, UGC 1810 will devour its galactic sidekicks over the next billion years and settle into a classic spiral form.
Titan’s methane-based hydrologic cycle makes it one of the Solar System’s most geologically diverse bodies. There are lakes of methane, methane rainfall, and even “snow” made of complex organic molecules. But all of that detail is hidden under the moon’s dense, hazy atmosphere.
The map is based on radar, visible, and infrared images from the Cassini mission. The Cassini mission ended in September 2017 when it was directed to crash into Saturn. But even after two years, scientists are still going through Cassini’s data and producing studies like this one.
Using uranium-lead dating, a research team led by Lida Xing from the China University of Geosciences and Michael Caldwell from the University of Alberta dated the fossils to about 99 million years old. A technique called synchrotron x-ray micro–computed tomography allowed the researchers to get a close look at the tiny specimens inside the amber without having to break them apart.
Astronomers have been wrestling with a few puzzles about the neighborhood for a while now. First, there's just not nearly as much stuff out there, all told, as they would expect. Also, it's odd that Neptune is more massive than the closer-in Uranus. And many of the small objects in the outer swath — like Sedna, a strange dwarf planet — follow extreme, stretched orbits at stark angles to the rest of the solar system's more orderly inhabitants.
Those quirks suggest that something must have stirred up the pot after the planets and large moons clumped together and formed out of the cloud of dust surrounding our sun early in its life. One possible culprit is a star that might have slipped next to our solar system and tugged objects off their original paths, throwing some out of the solar system entirely and skewing the orbits of others.
Ben-Gurion University of the Negev (Beer-Sheva, Israel) and University of Washington (Seattle) researchers have developed a new generic method to detect fake accounts on most types of social networks, including Facebook and Twitter. According to a new study in Social Network Analysis and Mining, the new method is based on the assumption that fake accounts tend to establish improbable links to other users in the networks.The algorithm consists of two main iterations based on machine-learning algorithms. The first constructs a link prediction classifier that can estimate, with high accuracy, the probability of a link existing between two users. The second iteration generates a new set of meta-features based on the features created by the link prediction classifier. Lastly, the researchers used these meta-features and constructed a generic classifier that can detect fake profiles in a variety of online social networks.
Lead author Dr Massimo Bernardi, Curator at MUSE and Research associate at Bristol's School of Earth Sciences, said: "We were excited to see that the footprints and skeletons told the same story. We had been studying the footprints in the Dolomites for some time, and it's amazing how clear cut the change from 'no dinosaurs' to 'all dinosaurs' was."
The point of explosion of dinosaurs matches the end of the Carnian Pluvial Episode, a time when climates shuttled from dry to humid and back to dry again. There were massive eruptions in western Canada, represented today by the great Wrangellia basalts -- these drove bursts of global warming, acid rain, and killing on land and in the oceans.
Astronauts aboard the International Space Station captured this photo while flying over the western United States. The wide field of view stretches from the Sierra Nevada of California to the Columbia Plateau of Oregon and the Snake River Valley of Idaho.
On November 14, Operation IceBridge scientist John Sonntag took this photograph of ice in the Weddell Sea, a part of the Southern Ocean off the Antarctic Peninsula. The geometric shapes are due to a phenomenon known as “finger rafting,” which occurs when two floes of thin ice collide. As a result of the collision, blocks of ice slide above and below each other in a pattern that resembles a zipper or interlocking fingers. Brine expelled from the ice forms a solution that acts as a lubricant. For finger rafting to occur, it’s critical that the ice be thin—calculations suggest no more than 8 inches, or 20 centimeters. Any thicker and the ice loses its flexibility. Without flexibility, thicker ice floes that collide can result in a big pile up known as “ridging.”
A streak of lightning in the skies over Japan has generated positrons — the antimatter equivalents of electrons — and radioactive carbon-14, confirming a theoretical prediction, according to a paper published in Nature on 22 November.
NASA — After more than 13 years at Saturn, and with its fate sealed, NASA’s Cassini spacecraft bid farewell to the Saturnian system by firing the shutters of its wide-angle camera and capturing this last, full mosaic of Saturn and its rings two days before the spacecraft’s dramatic plunge into the planet’s atmosphere.
For the first time, a science experiment has measured Earth's ability to absorb neutrinos -- the smaller-than-an-atom particles that zoom throughout space and through us by the trillions every second at nearly the speed of light.
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