The meteor that starred in a thousand and one tweets as it shot across the Siberian sky last February apparently had a rough history.

The Chelyabinsk meteor, estimated to have been 55-65 feet in diameter before breaking up, may have had previous fiery encounters — either colliding into another body in the solar system or traveling too close to the Sun — before its spectacular crash to Earth, according to analysis of fragments from its crust and interior.

Hints of Heat

Presenting the new findings at a geochemical conference today in Florence, Italy, Victor Sharygin of Novosibirsk's Institute of Geology and Mineralogy said a detailed mineral analysis of fragments of the meteorite revealed some anomalies suggesting the rock had previously been melted.

Dividing the pieces into different gradations of color and structure, the team identified a concentration of dark fragments composed of fine-grained material formed by extremely intense melting. The dark fragments were distinct from the meteorite's fusion crust, a thin layer that melts and then solidifies as the rock travels through Earth's atmosphere. The dark fragments' structure included what the team described as "spherical bubbles," either encrusted with oxide, silicate and metal or filled with metal and sulfide.

A major hi-tech Russian military research center has unveiled what appears to be a prototype of a next-generation combat suit. The stunning gear, resembling Star Wars outfits, will be worn by Russian soldiers on future battlefields.

The prototype features a helmet covering the soldier's face and cutting-edge body armor.

The next-generation combat gear also includes a powered exoskeleton to help increase performance and stamina while fighting.

The prototype was unveiled on Thursday at the opening of Russia's largest high-tech prototyping center at the National University of Science and Technology (MISIS) in Moscow.

A top astrophysicist says a city-destroying asteroid strike could take us by surprise.

Profressor Alan Fitzsimmons says that an event similar to the 1908 meteoroid explosion over the Tunguska region of Russia could happen again.

The meteor exploded above the Earth, levelling 80 million trees across an area of 800 square miles. China to send people to live on asteroids. Because of the remote location, no-one was killed - but if it had happened over a city the devastation would have been huge.

Uranus is a strange place. Among many of its quirks is that it has the most unusual magnetic field in the solar system. Unlike Earth and many other planets, this field is not closely aligned with its rotational axis—it's tilted by 60 degrees. Added to this is the fact that Uranus rotates on its side as it circles the sun.

This strange arrangement causes Uranus's magnetic field, also known as its magnetosphere, to flip open and closed on a daily basis, new research suggests. When closed, it acts like an umbrella to deflect solar wind, the continual stream of charged particles produced by the sun that perpetually bombard Uranus and other planets. But when it's open, these energized particles rush in and get trapped there.

To help picture the arrangement, Georgia Institute of Technology professor Carol Paty suggests visualizing a child cartwheeling toward you—you'd see hands, then feet, then hands again, over and over. The hands represent an open magnetosphere, while the feet represents a closed orientation. And it keeps going like this, toggling back and forth about once every Uranian day, which lasts over 17 (earthly) hours.

After many delays that disappointed space fans around the U.S., NASA finally managed to launch its mission early Thursday to, for the first time, create ephemeral, glowing clouds.

In other words, NASA created human-caused auroras, of sorts.

The suborbital sounding rocket took flight at 4:25 a.m. ET Thursday from NASA's Wallops Flight Facility in Virginia and released its payload — which consisted of 10 vapor-filled canisters — shortly afterwards.

Once at altitude, those canisters produced green-blue and red artificial clouds that should allow scientists to learn more about how particles move through space.

An international group of researchers has dated a large volcanic eruption in Iceland to within a few months. The eruption, which is the oldest volcanic eruption to be precisely dated at high northern latitudes, occurred shortly before the first permanent human settlements were established, when parts of the now mostly treeless island were still covered with forest.

The team, which included volcanologists, climatologists, geographers and historians among others, used a combination of scientific and historical evidence to pinpoint the eruption date of the Katla volcano between late 822 CE and early 823 CE, decades before the earliest settlers arrived. Their results are reported in the journal Geology.

In a similar way to how fossils can be used to understand the development and evolution of life on Earth, different types of environmental evidence can be used to understand what the Earth's climate was like in the past and why. The 'fingerprints' contained in tree rings and ice cores help scientists to estimate past climatic conditions and extend our understanding of the interaction between humans and the environment hundreds and thousands of years back in time.

Researchers at the University of Texas at Austin recently completed a comprehensive study illustrating the effects of smartphones on the human brain. What they found was that 'smart' phones actually make us dumb.

According to the study, Brain Drain: The Mere Presence of One's Own Smartphone Reduces Available Cognitive Capacity, having a smartphone around is a definitive way to lower our cognitive ability.

According to the study's authors, Adrian F. Ward, Kristen Duke, Ayelet Gneezy, and Maarten W. Bos, results from two experiments indicate that even when people are successful at maintaining sustained attention—as when avoiding the temptation to check their phones—the mere presence of these devices reduces available cognitive capacity. Moreover, these cognitive costs are highest for those highest in smartphone dependence. We conclude by discussing the practical implications of this smartphone-induced brain drain for consumer decision-making and consumer welfare.

High up in the clear blue noontime sky, the sun appears to be much the same day-in, day-out, year after year.

But astronomers have long known that this is not true. The sun does change. Properly-filtered telescopes reveal a fiery disk often speckled with dark sunspots. Sunspots are strongly magnetized, and they crackle with solar flares—magnetic explosions that illuminate Earth with flashes of X-rays and extreme ultraviolet radiation. The sun is a seething mass of activity.

Until it's not. Every 11 years or so, sunspots fade away, bringing a period of relative calm.

"This is called solar minimum," says Dean Pesnell of NASA's Goddard Space Flight Center in Greenbelt, MD. "And it's a regular part of the sunspot cycle."

The sun is heading toward solar minimum now. Sunspot counts were relatively high in 2014, and now they are sliding toward a low point expected in 2019-2020.

Dating back to the first century, scientists, philosophers and reporters have noted the occasional occurrence of "bright nights," when an unexplained glow in the night sky lets observers see distant mountains, read a newspaper or check their watch.

A new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union, uses satellite data to present a possible explanation for these puzzling historical phenomena.

The authors suggest that when waves in the upper atmosphere converge over specific locations on Earth, it amplifies naturally occurring airglow, a faint light in the night sky that often appears green due to the activities of atoms of oxygen in the high atmosphere. Normally, people don't notice airglow, but on bright nights it can become visible to the naked eye, producing the unexplained glow detailed in historical observations.

Few, if any, people observe bright nights anymore due to widespread light pollution, but the new findings show that they can be detected by scientists and may still be noticeable in remote areas. Bright airglow can be a concern for astronomers, who must contend with the extra light while making observations with telescopes.

"Bright nights do exist, and they're part of the variability of airglow that can be observed with satellite instruments," said Gordon Shepherd, an aeronomer at York University in Toronto, Canada, and lead author of the new study.

A historical mystery

Historical accounts of bright nights go back centuries. Pliny the Elder described bright nights, saying, "The phenomenon commonly called 'nocturnal sun', i.e. a light emanating from the sky during the night, has been seen during the consulate of C. Caecilius and Cn. Papirius (~ 113 BCE), and many other times, giving an appearance of day during the night."

It's a classic conundrum: while rushing to get to an important meeting or appointment on time, you spot a stranger in distress. How do you decide whether to stop and help, or continue on your way?

A new study by neuroscientists at Duke and Stanford University sheds light on how the brain coordinates these complex decisions involving altruism and empathy. The answer lies in the way multiple areas of the brain collaborate to produce the decision, rather than just one area or another making the call.

"The brain is more than just the sum of its individual parts," said Jana Schaich Borg, assistant research professor in the Social Science Research Institute and the Center for Cognitive Neuroscience at Duke.

Using a technique that combines electrical monitoring of brain activity with machine learning, the team was able to tune into the brain chatter of rats engaged in helping other rats.