A study of 12 million Facebook users suggests that using Facebook is associated with living longer.
The University of California research confirms what scientists have known for a long time about the offline world: people who have stronger social networks live longer.
"Interacting online seems to be healthy when the online activity is moderate and complements interactions offline," study author William Hobbs says.
"It is only on the extreme end, spending a lot of time online with little evidence of being connected to people, that we see a negative association."
People with average or large social networks, in the top 50 to 30 per cent, lived longer than those in the lowest 10 - a finding consistent with classic studies of offline relationships and longevity.
Those on Facebook with highest levels of offline social integration - as measured by posting more photos, which suggests face-to-face social activity - have the greatest longevity.
Online-only social interactions, like writing wall posts and messages, showed a non-linear relationship: moderate levels were associated with the lowest mortality.
Scientists from the European Southern Observatory have made new observations of the Pillars of Destruction in the far-away Carina Nebula using an instrument mounted on their Very Large Telescope called MUSE.
In contrast to the Pillars of Creation in the Eagle Nebula, the spires and pillars in the new images are vast clouds of dust and gas within a hub of star formation about 7500 light years away.
MUSE was able to create thousands of images of the Carina Nebula at the same time, each at a different wavelength of light, allowing astronomers to map out the chemical and physical properties of the material at different points in the nebula.
The images demonstrated how one of the first consequences of the formation of a massive star is that it starts to destroy the cloud from which it was born.
The idea that massive stars will have a considerable effect on what's around them is not new: such stars are known to blast out vast quantities of powerful, ionising radiation - emission with enough energy to strip atoms of their orbiting electrons.
Before now, however, it had been hard for scientists to secure observational evidence of the interplay between such stars and their surroundings.
Locker room talk
Research from the University of Arizona suggests that athletes might perform better when reminded of something a bit grim: their impending death.
In two new studies, basketball-playing participants scored more points after being presented with death-related prompts, either direct questions about their own mortality or a more subtle, visual reminder of death.
The researchers say the improved performance is the result of a subconscious effort to boost self-esteem, which is a protective buffer against fear of death, according to psychology's terror management theory.
"Terror management theory talks about striving for self-esteem and why we want to accomplish things in our lives and be successful," study co-author Uri Lifshin says.
"Self-esteem gives you a feeling that you're part of something bigger, that you have a chance for immortality, that you have meaning, that you're not just a sack of meat," Lifshin says.
Spinach is no longer just a superfood: by embedding leaves with carbon nanotubes, engineers at MIT have transformed spinach plants into sensors that can detect explosives and wirelessly relay that information to a handheld device similar to a smartphone.
It's one of the first demonstrations of engineering electronic systems into plants, an approach called "plant nanobionics".
The plants are designed to detect chemical compounds known as nitroaromatics, which are often used in landmines and other explosives.
When one of these chemicals is present in the groundwater sampled naturally by the plant, carbon nanotubes embedded in the plant leaves emit a fluorescent signal that can be read with an infrared camera.
The camera can be attached to a small computer similar to a smartphone, which then sends an email to the user.
Weird moon explained?
The moon, Earth's closest neighbour, is among the strangest planetary bodies in the solar system.
Its orbit lies unusually far away from Earth, with a surprisingly large orbital tilt, and it's long been thought that an impact from a large object, billions of years ago, eventually formed the moon and set the quirky partnership in play.
A new study, based on numerical models of the moon's explosive formation and the evolution of the Earth-moon system, comes close to piecing together a scenario that accounts for these characteristics.
The paper suggests the impact that formed the moon also caused calamitous changes to Earth's rotation and the tilt of its spin axis.
Its authors, from the University of Maryland, propose that the impact sent Earth spinning much faster, and at a much steeper tilt, than it does today.
In the several billion years since, complex interactions between Earth, the moon and sun have smoothed out many of these changes, resulting in the Earth-moon system that we see today.
Under the hypothesised scenario, the remaining anomalies in the moon's orbit are relics of the Earth-moon system's explosive past.