Planet Mercury's metal-rich composition is a puzzle in planetary science. According to a new simulation, Mercury and other unusually metal-rich objects in the solar system may be relics left behind by collisions in the early solar system that built the other planets.

The migration of tropical fish poses a serious threat to the areas they invade, because they overgraze on kelp forests and seagrass meadows. The harmful impact of tropical fish is already evident in southern Japanese waters and the eastern Mediterranean, where there have been dramatic declines in kelps.

There is also emerging evidence in Australia and the US that the spread of tropical fish towards the poles is causing damage in the areas they enter.

The authors blame the increased fish on warming oceans due to climate change that have led to hotspots in regions where the currents that transport warm tropical waters towards the poles are strengthening.

If you are having fun rather than doing exercise because you are worried about your health, you'll eat less, according to a new paper which delves into how to market to your brain.

Some people really like to run, or they look forward to exercise. They are probably already thinking about food consumption because they recognize that they did the work. Other people have painted themselves into a psychological corner - they think of exercise and workouts and calories and then eat more afterward. It's well known that most people tend to undercount calories ingested and overcount those in a workout.

DURHAM, N.C. – The changing dynamic of health studies driven by "big data" research projects will empower patients to become active participants who provide real-time information such as symptoms, side effects and clinical outcomes, according to researchers at Duke Medicine.

The analysis, published in the July 2014 issue of Health Affairs, lays out a new paradigm for health research, particularly comparative effectiveness studies that are designed to assess which therapies work best in routine clinical practice.

One of the first predators on land, a 410-million-year-old arachnid, has been virtually brought back to life. Paleontologists used exceptionally preserved fossils from the Natural History Museum in London to create the video showing the most likely walking gait of the animal.

The scientists used the fossils - thin slices of rock showing the animal's cross-section - to deduce the range of motion in the limbs of this ancient, extinct early relative of the spiders. From this, and comparisons to living arachnids, the researchers used the open source computer graphic program  Blender to create a video showing the animals walking.

Astronomers have studied the carbon monoxide in ALESS65, a galaxy over 12 billion light years away, and found that it's literally running out of gas. The future is not dark, it's 'red and dead'.

ALESS65 was observed by the Atacama Large Millimeter Array (ALMA) in 2011 and is one of few known distant galaxies to contain carbon monoxide.

 While our galaxy, the Milky Way, has about 5 billion years before it runs out of fuel and becomes 'red and dead', ALESS65 is a gas guzzler and only has 10s of millions of years left – that is very rapid, in astronomical terms.