Recent claims of potential biosignatures on the exoplanet K2-18b have been challenged by researchers at the University of Chicago. Their analysis suggests that the detection of dimethyl sulfide may be inconclusive due to overlapping signals from non-biological molecules, emphasizing the limitations of current detection technology and urging caution against premature conclusions.

A research paper proposes that advanced alien civilizations might be terraforming planets and spreading life through panspermia. It suggests that similarities among clustered planets could indicate extraterrestrial life, while acknowledging the challenges in detecting such life. This approach sidesteps the fundamental questions of life's origins.

That life might have come to earth traveling through outer space used to be a fringe theory called ‘panspermia’. But in the past decade or so, we have seen an interesting shift in how scientists regard the idea. Let’s take at one new study that might support ‘panspermia,’ as well as other facts that support the theory.

Natural selection allows animals – including humans – to slowly adapt to their environments over tens of thousands of years. Unfortunately for us humans, we’re quickly changing our environments and lifestyles, building sprawling cities and working at desks for 10 hours a day. According to a new paper, we now have good evidence that humans are no longer fit to live in the world we’ve created.

New observatories and spacecraft missions are probing environments in our solar system that could potentially host life but have long remained hidden. Icy moons like Saturn’s Enceladus and Jupiter’s Europa likely contain oceans beneath frozen outer shells. But a layer of ice prohibits space probes from sampling them directly. Exploring these icy moons is almost forensic: Their surfaces keep aContinue reading "Scientists used a method from ecology to identify whether icy moons could hold conditions for life"

The post Scientists used a method from ecology to identify whether icy moons could hold conditions for life appeared first on Astronomy Magazine.

Wild chimpanzees in Uganda split into two separate communities and later engaged in deadly attacks against each other. Researchers believe the conflict shows how social relationships alone can fuel polarization and violence. The world’s largest known community of wild chimpanzees has permanently divided into two separate groups. Researchers from the University of Texas at Austin [...]

A new AI framework called MouseMapper allows scientists to examine disease-related changes across the entire body at cellular resolution. Obesity does much more than affect metabolism and fat storage. It also changes immune activity, nerve structure, and tissue organization throughout the body, raising the risk of conditions such as type 2 diabetes, cardiovascular disease, stroke, [...]

Scientists identified phosphatidylcholine loss as a key driver of mitochondrial aging and showed that restoring it can rejuvenate cellular energy networks. Why do cells age, and why do people gradually lose energy and vitality over time? Scientists have long focused on mitochondria, the tiny structures inside cells responsible for producing energy. Researchers now understand that [...]

New research suggests a widely used herbicide may have subtle but significant effects on honeybees. Growing flowering plants for pollinator gardens, farms, and home landscapes often requires herbicides to control weeds. Honeybees are naturally drawn to these areas and are essential for pollination. But researchers wanted to know what happens when bees are exposed to [...]

Scientists have identified supermagnetic macrophages in the livers of homing pigeons (Columba livia domestica) that appear essential for navigation when the Sun is not visible, pointing to an entirely new mechanism for animal magnetoreception.

The post Pigeons May Sense Earth’s Magnetic Field Using Superparamagnetic Immune Cells in Their Livers appeared first on Sci.News: Breaking Science News.

Researchers suggest that old psychoanalytic ideas and modern brain science may be describing the same mental processes from different angles. More than a century after Sigmund Freud developed his influential theories of the mind, some researchers believe modern neuroscience may be arriving at surprisingly similar conclusions. A new paper published in the neurocognitive journal Entropy [...]

Field notebooks from the late Richard Köhler allowed researchers to finally catalog a remarkable fossil tarpon from Aotearoa New Zealand. Recently disclosed notebooks from a late paleontologist supplied the missing details researchers needed to complete their study of a “remarkable” fossil found nearly 30 years ago. Dr. Richard Köhler discovered the fossil fish in 1999 [...]

For 15 years, Sébastien Fontaine has been trying to kill dirt. The biochemist, who runs a lab at the French National Institute for Agriculture, Food, and Environment, wanted to know how much carbon is released by soil — just dirt alone, completely devoid of life. His team sealed dirt into jars and blasted them with sterilizing gamma radiation. Then they waited for the carbon dioxide released by…

Source

Earth has many unique features for a planet, such as a magnetic field, a large moon, and plate tectonics. It’s also the only planet we know of that harbors life. These facts form the basis of the Rare Earth hypothesis, which posits that we haven’t found aliens because other planets in the Galaxy probably don’t have all the right conditions for life. 

Another characteristic of Earth is that about 30% of its surface is land and about 70% is ocean. Recently, Columbia University Assistant Professor David Kipping investigated whether the proportion of Earth’s surface covered by dry land versus ocean, or its land fraction, is another reason Earth is habitable not only for simple single-celled organisms, but also for intelligent species like humans. 

To test this hypothesis, Kipping created 4 statistical models of planets with different land fractions that intelligent aliens could potentially evolve on. First, he created an equation to describe the likelihood that a planet in its star’s habitable zone has a particular land fraction, known as a probability distribution. Kipping weighted this probability distribution toward the extreme ends, making it more likely that a planet would be covered by a single huge landmass or a single vast ocean than by a mix of both, as on Earth. 

Kipping then incorporated this land fraction probability distribution into his statistical models to calculate the probability that a random planet will have that land fraction and host intelligent life. The 4 scenarios Kipping tested were: 1) that intelligent life is more likely to emerge on land-dominated planets, 2) that it’s more likely to emerge on ocean-dominated planets, 3) that it’s more likely to emerge on planets with roughly equal amounts of land and ocean, and 4) that its emergence is independent of a planet’s land fraction. 

As a first step in determining the kinds of planets intelligent aliens would tend to emerge on, Kipping used each model to predict the probability that intelligent life would emerge on a planet with the same land fraction as Earth. He then compared these probabilities by calculating the ratios between each value. Because Earth is the only known planet with intelligent life, a model that predicted a greater probability for humanity’s existence on Earth would be more likely to reflect reality.

Kipping considered it strong evidence that a given model was more realistic than another if the ratio between 2 of them was greater than 10, meaning one model was 10 times more likely to predict the existence of Earth and humanity. Kipping found that no comparison of any 2 models passed this threshold. However, the models assuming that intelligent life prefers ocean-dominated planets or planets with a land-ocean balance were 2.5 and 3 times more likely to predict the existence of humanity than the model assuming that intelligent life prefers land-dominated planets. Additionally, the model assuming that intelligent life prefers a land-ocean balance was always more likely to predict humanity than any other model, though marginally. 

Kipping also addressed whether finding more planets with intelligent life would affect which model was deemed most realistic, for example, if scientists discovered conclusive evidence of life on Mars in its distant past. Here, Kipping identified 2 complications. First, it’s uncertain how much of Mars’s surface was once covered by water – some estimate it had a land fraction as high as 81%, while others estimate it was as low as 25%. Second, proving that Mars once had life would not prove it once had intelligent life.

Regardless, Kipping reran the models assuming that ancient Mars had a land fraction comparable to Earth’s. Adding this second data point produced ratios similar to those in the earlier Earth-only calculations, meaning it still didn’t make any single model 10 times more likely to predict the existence of humans and Martians, respectively. 

Kipping then took the 10-times threshold and reversed the calculations to find what conditions would exceed it. In doing so, he calculated that astronomers would need to find 14 other planets with intelligent life and known land fractions to robustly determine whether intelligent life is more likely to occur on desert planets, ocean planets, balanced planets, or without bias.

Kipping concluded that he can’t yet definitively state whether there is something special about Earth’s land fraction when it comes to producing intelligent species. However, Earth’s existence would suggest that intelligent life is unlikely to favor extreme desert planets, so the Milky Way probably isn’t filled with Tatooines and Jakkus. And while his analysis doesn’t debunk the Rare Earth hypothesis, it does undermine the argument that Earth’s ocean size explains why Earth is rare. 

The post Is Earth’s water why intelligent life evolved here? appeared first on Sciworthy.

© James R.D. Scott / Getty Images

Stanford researchers have developed a microscope that can show how nanostructures interact inside living cells at the highest resolution achieved so far. The view into living cells just got better. Stanford researchers have merged two microscopy methods to build a unique instrument that can capture cell structures interacting in real time at an unprecedented resolution [...]

A sesame-seed-sized sea slug discovered in Taiwan is revealing a hidden world of tiny ocean life. A newly identified species of sea slug, so small that it is barely larger than a sesame seed, has been discovered in the coastal waters of Keelung, Taiwan. The tiny marine animal, named Thecacera sesama, features a translucent body [...]

The loss of a queen triggers intense battles for power among female wasps, disrupting the colony’s social structure. Surprisingly, other wasps avoid the fighting and keep the colony functioning by taking care of its most important daily tasks. What happens when a queen suddenly disappears from a wasp colony? According to new research led by [...]

A new evolutionary analysis suggests that modern blood and immune cells may preserve a 700-million-year legacy inherited from ancient single-celled ancestors. Long before humans, dinosaurs, or even fish existed, ancient single-celled organisms may have already carried the genetic blueprint for one of the body’s most important systems: blood. A new study from Kyoto University suggests [...]

Scientists are discovering that some of the cells linked to aging may also be key to staying healthy. A growing body of research is changing how scientists view one of aging biology’s most studied cell types: senescent cells, often called “zombie cells.” While these cells have long been associated with aging and chronic disease, new [...]