The moon is just a big rock in Earth's orbit now but things could have gone a lot differently in the distant past. In fact, there may have been two early windows of habitability for Luna.

In a new paper, astrobiologists say conditions on the lunar surface were sufficient to support simple lifeforms shortly after the moon formed from a debris disk 4 billion years ago and again during a peak in lunar volcanic activity around 3.5 billion years ago. During both periods, planetary scientists think the moon was spewing out large quantities of superheated volatile gases, including water vapor, from its interior.

If you are up for a job, and four other candidates are weak, your chances are obviously better than if four other candidates are strong. In the World Cup just completed, statistically there will always be a 'Group of Death", wherein a round-robin group will have three strong teams but only two can advance, meaning a world-class squad will be eliminated. 

Poker players know to bet low when the odds are only modestly better and to bet high when the statistics show the cards in hand are strong. Timing matters, in jobs, in games, in lots of things. 

Wrinkles and hair loss are perfectly natural aspects of aging - but science is all about defeating the nature that wants to kill us off.

One aspect of aging is a decline in mitochondrial function.

Everyone knows that water is a molecule in which a single oxygen atom is linked to two hydrogen atoms - H20.

But the story of water gets a lot more scientifically interesting the deeper you go. Water actually exists in two different forms, called isomers, at the molecular level.

They have almost identical physical properties, you can't tell the difference, but chemists can tell them apart by the relative orientation of the nuclear spins of the two hydrogen atoms.  They are called ortho- or para-water depending on whether the spins are aligned in the same or opposite direction.

Across Europe, 95 percent of people claim to have seen seen litter when they visited the coast - yet they say they don't litter. And they don't trust scientists, corporations or government to solve it, which leaves environmentalists who don't ever actually send people into the wilderness to clean up litter.

Marine litter is a big deal thanks to environmental publicity but it is highly exaggerated - think mercury in salmon, alar on apples, floating barges of garbage, estrogen in drinking water and more to get an idea of how these issues get magnified. 

Sub-Saharan Africa has around 80 million people infected with hepatitis B, a liver infection caused by the hepatitis B virus, but it infects around 250 million people worldwide. It can be a mild illness lasting a few weeks or a serious, lifelong condition. It is transmitted through blood and bodily fluids.  

An accurate diagnostic score that consists of inexpensive blood tests costing around $20 could help diagnose thousands of patients with hepatitis B in need of treatment in some of Africa's poorest regions, far more affordable than the $100-500 for current tests.