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ESA’s Rosetta spacecraft has found the water vapour from its target comet to be significantly different to that found on Earth. The discovery fuels the debate on the origin of our planet’s oceans.

The measurements were made in the month following the spacecraft’s arrival at Comet 67P/Churyumov–Gerasimenko on 6 August. It is one of the most anticipated early results of the mission, because the origin of Earth’s water is still an open question.

One of the leading hypotheses on Earth’s formation is that it was so hot when it formed 4.6 billion years ago that any original water content should have boiled off. But, today, two thirds of the surface is covered in water, so where did it come from?

The “warming hiatus” that has occurred over the last 15 years has been caused in part by small volcanic eruptions. Scientists have long known that volcanoes cool the atmosphere because of the sulfur dioxide that is expelled during eruptions. Droplets of sulfuric acid that form when the gas combines with oxygen in the upper atmosphere can persist for many months, reflecting sunlight away from Earth and lowering temperatures at the surface and in the lower atmosphere. Previous research suggested that early 21st-century eruptions might explain up to a third of the recent warming hiatus.

There is a simple solution to the problems of rampant consumerism, debt and a lifetime of servitude, writes Samuel Alexander - radical down-sizing to a truly tiny house. For a start, it's only big enough for the things you really need. And it's so cheap to build, that it's paid for from a month or two's salary. Just one question - what will you do with your freedom?

With one's housing requirements so easily met, and having escaped the iron grip of indebtedness, one would then be faced with the exhilarating but terrifying question of what to do with a life of freedom.

Denmark has long been one of the world’s leaders in wind power. The country of 5.6 million has set a goal of generating 50 percent of its power from clean energy sources by 2020 and aims to be entirely fossil fuel-free by 2050. Those goals, especially the one for 2020, are well achievable: Denmark has announced it scored 39.1 percent of its energy from wind in 2014.

The balmy islands of Seychelles couldn't feel farther from Antarctica, but their fossil corals could reveal much about the fate of polar ice sheets.

About 125,000 years ago, the average global temperature was only slightly warmer, but sea levels rose high enough to submerge the locations of many of today's coastal cities. Understanding what caused seas to rise then could shed light on how to protect those cities today.