Scientists call it the epoch of reionization, the period in which a newborn universe went from darkness to light as the first stars, galaxies and black holes began forming and radiating energy.

In a paper published Thursday in Nature, researchers are challenging one long-held conception about how quickly the universe began warming during this transition period.

Based on observations of X-ray emissions from binary star systems, as well as new mathematical models, cosmologists at Tel Aviv University and Harvard say that heating of the universe progressed much more slowly, and uniformly, than...

How do young, naive salmon with no migratory experience somehow voyage through vast, shifting ocean waters to wind up at specific feeding grounds that are hundreds, even thousands, of kilometers away from where they were hatched? It turns out these fish may have a magnetic ‘map’ in their heads that enable them to sense and navigate using the Earth’s magnetic fields rather like a GPS.

The findings, published in Current Biology, “likely explain the extraordinary navigational abilities evident in many long-distance underwater migrants,” the study authors wrote.

Resea...

On the 529th day of Curiosity's journey on Mars, the rover turned its cameras to the skies and sent back this humbling image of Earth and our moon.

Our planet and moon appear as two small dots in the Martian sky, no bigger or more significant than Mars or Jupiter look to us.

The image was taken Jan. 31 Earth time, 80 minutes after the sun set on Mars. Although Earth and the moon look small, they are currently the two brightest bodies in the Martian night sky, according to a release from the Jet Propulsion Laboratory. 

If you or I were standing on the Martian surface, we would have no trouble...

A generic blood pressure drug could prevent hyperactive brain cell firing associated with early stages of autism spectrum disorder, according to a new study.

Injecting pregnant mice with Bumetanide, a diuretic, appears to correct a developmental switch flipped during childbirth that reverses the firing characteristics of neurons in newborns, according to a study published online Thursday in the journal Science.

Bumetanide mimics the effects of oxytocin, a hormone released during labor that helps protect newborns from the stresses and complications of birth, the study found. That surge of...

NASA's HiRISE mission has spotted a crater on Mars that is dazzling and so new that just four years ago it didn't exist.

The crater is 100 feet wide and shaped liked a starburst. It was caused by a small-ish space rock that slammed into the planet and exploded between July  2010 and May 2012. The impact sent debris as far as nine miles from the crater site. 

The images above were taken last November and released this week. The first image, with blue overtones, is color enhanced. The center of the image is especially blue, because it is void of the red dust that covers most of the Martian...

Warning: Being a firstborn may be hazardous to your health.

So suggests a small study of middle-aged men in New Zealand. Compared with  their younger brothers, the firstborns weighed more and were less sensitive to insulin.

Researchers had recruited the guys to be part of clinical trials testing whether olive leaf extract or krill oil could improve their metabolic health. All of the volunteers were between the ages of 35 and 55, and all were overweight, with a body mass index between 25 and 30.

To study the effects of birth order, they pulled out data from trial participants who were either...

NASA’s Mars rover Curiosity is poised to tip its wheels over the crest of a dune called Dingo Gap, down a path that could lead to a promising new target for the robotic explorer to drill. But the rover has remained perched on the edge as its team decided whether to take the plunge down potentially hazardous terrain.

“The rover today literally has its two front wheels at the crest of the dune … and if all goes well, we should be down and off of it tomorrow,” said Caltech geologist John Grotzinger, lead scientist for the Mars Science Laboratory mission. At about a yard...

Chinese health authorities have identified a brand-new type of bird flu that killed an elderly woman in November and infected at least one other person in January.

That trend prompted the experts to call for stepped-up surveillance to track the new H10N8 influenza virus in poultry markets and in human patients.

“The pandemic potential of this novel virus should not be underestimated,” the medical team wrote in a report published Wednesday by the journal Lancet.

Genetic analysis of the H10N8 influenza virus revealed that it has two mutations that make flu viruses more virulent in...

The human hand is a wonder of strength, sensitivity and discrimination — not only because of those four fingers and the opposable thumb, but also because of the human brain that controls it. No wonder, then, that for those who design hand prostheses, re-creating the natural dexterity of the brain-powered hand is a daunting challenge.

But a new study demonstrates that, with the aid of some artificial sensors and electrodes sunk into a user’s arm, a prosthetic hand can be made to detect the need for a firm grasp or a light touch, to make fine distinctions between an object’s...

Want to hear as well as Stevie Wonder or the late Ray Charles? A blindfold not only might help, it could re-wire your brain in the process, a new study suggests.

The study, in mice, was the first to show evidence on a cellular level of a phenomenon that has been relatively well chronicled behaviorally – damage to one sense can be compensated with strength in another. And that compensation can happen later in life, when the brain is generally less susceptible to rewiring, the study found.

Blinding micefor about a week altered synapses connecting the thalamus to the auditory cortex,...

Here’s one solution to the National Football League’s concussion problem: Stop playing at sea level.

Researchers have found that concussion rates are about 30% lower in games played at higher altitudes.

The finding was based on an analysis of all 300 concussions reported during the first 16 weeks of regular-season NFL games in 2012 and 2013. (Week 17 data were not available, since only playoff-bound teams release them.)

For every 10,000 times a player suited up, there were 64.3 concussions. But that figure varied with elevation.

The concussion rate at the 24 stadiums situated less...