In the grand club of galaxies, the Milky Way is increasingly looking like an outlier. This is a looming challenge for cosmology

It has long been assumed that our galaxy is a classic example of many of the galaxies that pepper the cosmos. That's important, because astronomers have intensely studied the Milky Way and, with this assumption, can use what they find to inform their view of the wider universe.

But what if our neck of the woods isn't that normal after all? It would be a big deal for cosmologists and astronomers. That question is coming to the fore because yet more observations suggest that our galaxy is an "outlier" in important ways. And if it isn't a representative galaxy, a fair chunk of astronomical thinking could be out of kilter.

Ice stream retreats under a cold climate

Why did the Jakobshavn Isbræ ice stream in West Greenland retreat under a cold climate period called the Younger Dryas?

A research article, published in Nature Communications, shows that a warmer ocean surface in central-eastern Baffin Bay triggered the ice retreat during this cold period. The Younger Dryas period occurred 12,900-11,700 years ago and interrupted the atmospheric warming after the last ice age.

Signal Detection Theory is a popular and well-established idea that has influenced behavioral science for around 50 years. Essentially, the theory holds that in a predator-prey relationship, prey animals will show more wariness and be more prone to flee as predators become more common. Danger signals are ambiguous, so in what appears to be a threatening situation, animals are better off running than hanging around to see if a predator really does strike.

Now Pete Trimmer, a postdoctoral research at UC Davis, has taken a fresh look at signal detection theory and come up with what at first look like counterintuitive results. In many cases, he says, animals should actually become less cautious as the risk of predation rises.

The problem with conventional signal detection theory, Trimmer says, is that it only considers one decision at a time, in isolation. But in reality, animals may have to make multiple connected decisions and have to take into account the effects of decisions over time.

Trimmer, graduate student Sean Ehlman and Professor Andy Sih at UC Davis, with mathematician John McNamara at the University of Bristol, U.K. developed a new model that they call state-dependent detection theory or SDDT. The work is published Oct. 18 in the journal Proceedings of the Royal Society B.

Scientists have long debated whether or not a mysterious ninth planet lurks at the edge of our solar system.

Some astronomers think the existence of the alleged planet - which they claim is 10 times the size of Earth - explains the bizarre way some distant objects in space move.

Now scientists have found new evidence that 'Planet Nine' exists by building simulations of the solar system with different sizes of the celestial body.

They found that the unusual orbits of distant rocks in our system can be explained by the presence of a ninth planet with the dimensions scientists have proposed.

Last week, Nasa highlighted five lines of evidence pointing to the existence of the elusive world, and said that imagining Planet Nine does not exist generates more problems than it solves.

A spy satellite atop an Atlas V rocket blasted off on a classified mission early Sunday morning from Cape Canaveral Air Force Station in Florida.

US officials have not revealed what the satellite will be doing or what its orbit will be, making it the second secret spy craft launched by the country in just three weeks.

Some have suggested it will use sensors to gather data on an enemy's electronic defence network, including radars, surface-to-air missile systems and aircraft.

The satellite, which launched at 3:28am ET (7:28 BST) yesterday, had experienced a week of delays due to poor weather and a faulty transmitter that had to be replaced.

Back in May, Google revealed its AutoML project; artificial intelligence (AI) designed to help them create other AIs.

Now, Google has announced that AutoML has beaten the human AI engineers at their own game by building machine-learning software that's more efficient and powerful than the best human-designed systems.

An AutoML system recently broke a record for categorising images by their content, scoring 82 percent.

While that's a relatively simple task, AutoML also beat the human-built system at a more complex task integral to autonomous robots and augmented reality: marking the location of multiple objects in an image.

The stereotype of a tortured genius may have a basis in reality after a new study found that people with higher IQs are more at risk of developing mental illness.

A team of US researchers surveyed 3,715 members of American Mensa with an IQ higher than 130. An "average IQ score" or "normal IQ score" can be defined as a score between 85 and 115.

The team asked the Mensa members to report whether they had been diagnoses with mental illnesses, including autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).

They were also asked to report mood and anxiety disorders, or whether the suspected they suffered from any mental illnesses that had yet to be diagnosed, as well as physiological diseases, like food allergies and asthma.

Japanese researchers have discovered a cavern stretching 50 kilometers beneath the surface of the moon. It is hoped that the huge subterranean area could be used as a lunar base for astronauts in the future, the Japan Aerospace Exploration Agency (JAXA) has said.

The cavern, believed to be a lava tube created about 3.5 billion years ago, could protect astronauts from the sun's radiation and cosmic rays when they build a base for exploration, according to Kyodo news.

The expansive cavity, located beneath an area with a group of volcanic domes called the Marius Hills, is about 100 meters wide, according to data taken by JAXA's lunar orbiter 'Kaguya.'

Beneath the peaceful rolling waves of a lake is a rumble, imperceptible to all but seismometers, that ripples into the earth like the waves ripple along the shore.

In a study published today in the Journal of Geophysical Research Solid Earth, scientists at the University of Utah report that these small seismic signals can aid science. As a record of wave motion in a lake, they can reveal when a lake freezes over and when it thaws. And as a small, constant source of seismic energy in the surrounding earth, lake microseisms can shine a light on the geology surrounding a lake. "It's kind of a new phenomenon," says Keith Koper, director of the University of Utah Seismograph Stations and co-author of the study. "We don't really know how it's created."
Discovering quaking lakes

Seismologists have long known that wind-driven ocean waves generate small seismic waves, called microseisms. These microseisms are generated as waves drag across the ocean floor or interact with each other. They are part of the background seismic noise in coastal areas.

"We've recently found that the waves on lakes actually generate these microseisms too," Koper says. Lake microseisms had been previously recorded near the Great Lakes, Canada's Great Slave Lake and Utah's own Great Salt Lake. In the paper, Koper and colleagues present additional observations from Yellowstone Lake and three lakes in China, exploring the characteristics of the respective lakes' microseisms.

The Earth's interior is still a mystery to us. While we have sent missions to probe the outer reaches of our Solar system, the deepest boreholes on Earth go down to only a few kilometres. The only way to learn what's going on deep inside our planet, in the core and the mantle, is by indirect methods.

Many of us might have seen those beautiful pictures of our round, blue planet taken from space, but did you know that our planet actually looks like a bumpy potato? It has its own share of deformations, non-uniform gravity because of the unequal distribution of mass and occasionally, mountains and valleys created by the movements of tectonic plates. Considering that around three-fourths of our planet's surface is made up of oceans, these deformities affect the shape of the oceans too. If we removed the tides and currents from the oceans on the planet, they would settle onto a smoothly undulating shape called a geoid, rising wherever there is high gravity, and sinking where gravity is low, creating what are known as "geoid anomalies." These highs and lows are generated by uneven mass distribution within the deep Earth.

One such point of low gravity is found just south of the Indian peninsula, called the Indian Ocean Geoid Low (IOGL). The geoid low spans a vast extent south of the Indian subcontinent, and is dominated by a significant low of minus 106 metres, or roughly 348 feet, south of Sri Lanka.

"The existence of the Indian Ocean geoid low is one of the most outstanding problems in Earth Sciences," said Attreyee Ghosh, an assistant professor at the Centre for Earth Sciences, Indian Institute of Science, in Bangalore, India. "It is the lowest geoid/gravity anomaly on Earth and so far no consensus existed regarding its source. It is remarkable as it means that there is some mass deficit in the deep mantle that's causing the low."

"A low gravitational potential would mean that the ocean surface itself would go down," she said. "So, for a 100 meter (328 feet) geoid low the ocean surface would dip down by 100 meters at that region."