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.

Forecasters at the National Oceanic and Atmospheric Administration predict a below-normal number of named storms in the upcoming 2026 Atlantic hurricane season.

Forecasters at the National Oceanic and Atmospheric Administration predict a below-normal number of named storms in the upcoming 2026 Atlantic hurricane season.

The Euphrates River fueled the "cradle of civilization," and a new study reveals the waterway was born of two other ancient rivers around 3.6 million years ago.

The Euphrates River fueled the "cradle of civilization," and a new study reveals the waterway was born of two other ancient rivers around 3.6 million years ago.

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.

ScienceAlert reports: In the molten ocean of iron churning in Earth's outer core, a section deep beneath the Pacific Ocean suddenly reversed direction and started moving eastward against the planet's usual westward flow. This happened in 2010, according to satellite measurements of Earth's magnetic field, and scientists are still trying to figure out what caused it... [I]t seemed to have a large, wave-like structure — as though a chunk of molten core material suddenly thought better of where it wanted to go, surging in the other direction... This finding suggests that there are processes that can influence it strongly enough to alter its behavior in bulk — and that our planet's interior may be more dynamic and variable than we thought. A new analysis captures what we know so far — and "It's from the roiling, molten, conducting metal at Earth's heart that the planetary magnetic field is generated... vital to our continued existence. It helps keep the atmosphere we breathe in and harmful cosmic radiation out."

Read more of this story at Slashdot.

Scientists discovered that Antarctica’s ice sheet became dramatically more climate-sensitive after crossing a critical threshold one million years ago. A new study published in Nature Geoscience suggests that Antarctica’s massive ice sheet underwent a major change about one million years ago, becoming far more responsive to shifts in Earth’s climate. The research, led by scientists [...]

Scientists say melting sea ice may have pushed the Arctic Ocean past a tipping point, triggering changes that could reshape marine life for decades. Scientists have identified what appears to be a major and potentially irreversible change in the Arctic Ocean. According to a new study, climate-driven sea ice loss has altered the region’s chemistry [...]

Iran is experiencing "water bankruptcy" that stems from decades of broken water governance and aggressive policies, and the current war is exacerbating the crisis.

Fingal's Cave is a hollow inside the Scottish island of Staffa that is characterized by massive, interlocking hexagonal columns of volcanic rock and astonishing acoustics.

Fires from March 7 airstrikes created a sulfur dioxide plume spanning 185,000 square miles.

Researchers have warned that the Thwaites Glacier, one of the largest glaciers in the world, is about to lose its eastern ice shelf. We spoke to marine geophysicist Robert Larter about what this means for the "Doomsday Glacier."

West Antarctica's "Doomsday Glacier" is on the brink of losing its ice shelf, further compromising the already melting ice mass and threatening to unleash devastating sea-level rises.

A 2015 satellite photo shows a series of golden tendrils surrounding Ghana's Lake Bosumtwi, which is considered sacred to the local Asante people. The lake and its surroundings were shaped by a massive meteor impact around 1 million years ago.

Jupiter dominates the Solar System’s architecture. At about 318 times Earth’s mass and orbiting far beyond Mars, it acts as...

The post If Jupiter Disappeared Would Earth Face More Asteroid Hits? appeared first on Curiosmos.

If Earth disappeared instantaneously, the first thing that would not happen is a crash. The Moon is not “hanging” over...

The post If Earth Vanishes What Happens to the Moon? appeared first on Curiosmos.

Iran is experiencing "water bankruptcy" that stems from decades of broken water governance and aggressive policies, and the current war is exacerbating the crisis.

Even the satellites are seeing red.

Even the satellites are seeing red.