Do you know where the solar system ends? Not really. We know it does, but picking a hard boundary is difficult.

And when it comes to anthropogenic emissions and air quality, it is hard to know for sure also. How much of CO2 is natural? How are we past the tipping point for CO2 levels while warming has not risen? 

How are emissions calculated? Different ranges of emission fluxes have been proposed by several studies, which have provided emissions at different spatial and temporal scales. Reconciling them all is difficult An EU funded project called Monitoring Atmospheric Composition&Climate II (MACC ll) seeks to hone in on real answers.

Most people feel comfortable conducting financial transactions on the Web, the cryptographic schemes that protect online banking and credit card purchases have proven their reliability over decades.

Pluto orbits the sun more than 29 times farther away than Earth, with a surface temperature estimated to be about 380 degrees below zero Fahrenheit.

The environment on Pluto, which 2 percent of astronomers voted on no longer being really a planet anyway, is far too cold to allow liquid water on its surface. Its moons are in the same frigid environment.

Pluto's remoteness and small size make it difficult to observe so take speculation about Charon, a moon of Pluto, having cracks in its surface and perhaps a subterranean ocean of liquid water, with a grain of otherworldly salt. In July of 2015, NASA's New Horizons spacecraft will be the first to visit Pluto and Charon, until then we have numerical models and a fair amount of educated guessing. 

Recent mass killings have again raised concern among lawmakers and the media about the possible connection between mental illness, and drugs to treat it, and gun violence.  Obviously someone who commits a mass shooting is mentally ill so renewed focus has been on the impact of a modern medical culture which over-medicates a lot of behavior. Guns have always been a part of American culture and individual murders are down, but a spate of mass shootings has occurred recently, causing people to search for a cause beyond simplistic 'ban guns' exploitation.

Heart attack is the leading natural killer worldwide, with up to one in two men and one in three women past the age of 40 having heart attacks in their lifetimes. What if one shot, similar to a vaccine, could prevent that?

Writing in Circulation Research, researchers show they have developed a “genome-editing” approach for permanently reducing cholesterol levels in mice through a single injection, a development that could reduce the risk of heart attacks in humans by 40 to 90 percent.

There is a common perception is that if you are sick, you sleep more, and some people do - but a new study found that sickness induced insomnia is quite common.

Fighting off illness – rather than the illness itself – causes sleep deprivation and affects memory, says University of Leicester biologist Dr. Eamonn Mallo.