Little more than half the size of our own moon, Pluto has always been presumed to be a dead, frozen planet only a few tens of degrees above absolute zero – literally a failed planet, officially demoted to ‘dwarf planet’ a few years ago. But could we be in for a surprise? Could the last dark corner of the solar system throw us a curveball?

NASA’s New Horizons probe has been speeding towards Pluto for almost a decade, getting a gravity assist from Jupiter in 2007 to help it cover the immense 5 billion kilometers to its target. Its cameras started to distinguish Pluto as more than just a speck of light around February of this year, but by April the images showed a hint of two blurry white polar caps, raising the intriguing possibility of ice deposits on its surface.

By early June the images were indicating not simply two polar caps but a more complex pattern of different light and dark regions including bands of lighter terrain as well as a large dark area, suggesting perhaps different geological zones, as well as a lumpy surface possibly indicative of large impact craters or maybe even a large chunk missing from one side.

Image Credit: NASA

Over the coming two weeks, the images should get much more detailed, enough to meet the primary goal of the mission to characterize the surface geology and morphology of both Pluto and its largest moon, Charon. However, travelling at 14 km/s, it will be going too fast to go into orbit around Pluto, so the plan is for it to take as many images and measurements as it can as it zips past the dwarf planet, something it will do in less than 4 minutes at around lunchtime on 14 July.

And then what? New Horizons will fly on into the Kuiper Belt, a huge region of small asteroids about twenty times wider than the asteroid belt between Mars and Jupiter. The ambition is to fly by some of these objects – but with its fuel almost gone, batteries fading and at the limit of its communications, it is pot luck what it will find. Any objects that it does encounter are likely to be no more than 50 km across, too small to see from Earth at that distance.

But Pluto is far from being the outer limit of our solar system. A handful of other dwarf planets have been found in recent years, the so-called Trans-Neptunian Objects (TNOs). TNOs range from a similar size to Pluto down to about a fifth of its diameter. The furthest, Sedna, orbits the sun a massive three times further out than Pluto. Sadly New Horizons will not reach any of them before its batteries run out, so the enigmatic worlds of the colourfully-named Eris, Makemake, Haumea, Sedna, Quaoar and Orcus will have to wait for another generation.

Other surprises have been found in the past few months. Another NASA probe, Dawn, is now in orbit around Ceres, the largest object in the asteroid belt beyond Mars, and roughly half the size of Pluto. For the most part, Ceres has looked much as you would expect an asteroid to look: a heavily cratered miniature version of our own moon. Except for one bizarre and so far unexplained feature – a series of extremely bright spots, so bright they look as though they’ve been painted on with reflective paint. Favourite theories so far are salt deposits or ice, both of which then beg the question of how they got there.

It seems that however far we go in our exploration of the solar system, surprises are always in store.

The Ceres bright spots imaged by Dawn from 4,400 km. This strange group of highly reflective areas are scattered over a region 90 km across. Image credit: NASA.

Releasing so much methane all at once jump-starts what has been, so far, a fairly slow and steady climate warming process. What makes this scenario particularly worrisome is that methane is a much more potent greenhouse gas than CO₂ – between 20 and 100 times more effective at warming the planet’s surface depending on whose estimates you believe. The net result of this nightmare scenario, also known as the clathrate gun hypothesis, is a rapid acceleration in global warming along with all the consequent bad effects for humankind.

Methane hydrates are found in subsea deposits in many parts of the world’s oceans including shallower areas of the Arctic Ocean as well as onshore in permafrost, but until recently this ‘arctic methane timebomb’ hypothesis that there could exist a tipping point at which gradual warming might suddenly trigger a mass release was just that, still a hypothesis.

But four years ago, a joint US-Russian expedition observed fountains of methane bubbles rising from the seafloor of the East Siberian Arctic Shelf. Last summer, a Swedish expedition found a whole lot more, with plumes up to a kilometre wide and methane concentrations 100 times the background concentration. More recently they have been observed offshore Svalbard in the Norwegian arctic too.

Methane bubbling to the surface in a lake in the Yamal permafrost. Image credit: Siberian Times and Vasily Bogoyavlensky

If that wasn’t enough, two years ago mysterious craters began appearing in the permafrost of the Yamal Peninsula, also in the Russian arctic. Just one or two at first, but last month twenty more were found in a survey of satellite images. The most credible explanation so far is that they are sinkholes that have filled with methane released from the surrounding permafrost, until the pressure build-up makes them explode outwards.

So is the arctic methane timebomb prophecy becoming a reality? Are we on the verge of climate calamity?

Unlike the near-universal agreement that humanmade CO₂ is responsible for global warming, scientific opinion is sharply divided over whether catastrophic release of methane from the arctic is likely or even possible.

Carolyn Ruppel of the USGS Gas Hydrates Project concluded a recent Nature review article on the subject by saying ‘catastrophic, widespread dissociation of methane gas hydrates will not be triggered by continued climate warming at contemporary rates (0.2^oC per decade; IPCC 2007) over timescales of a few hundred years. Most of Earth’s gas hydrates occur at low saturations and in sediments at such great depths below the seafloor or onshore permafrost that they will barely be affected by warming over even 103 years’, and made it even clearer in a follow-up TV interview by saying bluntly that the clathrate gun hypothesis was ‘nearly impossible’.

One of the Yamal Craters. Image credit: Siberian Times and Vasily Bogoyavlensky.

Others have supported this view by pointing out that if hydrates are so unstable one would expect to find high concentrations of methane during past global warm periods in records of past atmospheric composition, such as polar ice cores – yet no such correlation has been consistently observed.

On the other hand, computer simulations of warming seafloor gas hydrates have demonstrated that they can undergo rapid dissociation over timescales as short as decades, and the recent observations from the East Siberian Arctic unquestionably do show that significantly increased amounts of methane are being released as the arctic warms, although it is estimated to be still only 0.5 million tonnes per year.

Such gradual releases of methane from melting ice both on-land and subsea are to be expected as the climate warms, however that’s missing the point. The doomsday scenarios require not a gradual release but a rapid, catastrophic one – and as much as the climate pessimists may wish for it, there isn’t much hard evidence for such a scenario … yet.

There is no question that the arctic will play a key role in the future climate change of the planet, in fact it’s already happening thanks to the rapidly shrinking summer pack ice cover and the resulting change in albedo, leading to a warming of the Arctic Ocean and hence changing weather patterns. The resulting ‘wavier’ jet stream is thought to be the cause of the recent spate of more severe winter weather events in North America. But the jury is still out on whether runaway methane release is likely to add to the problem too.

The BICEP2 laboratory, located at the South Pole. Image courtesy BICEP2/Steffan Richter, Harvard University

For astrophysicists, the most exciting moment of the year was probably when a team of cosmologists working at the BICEP2 laboratory at the South Pole announced that they had detected the long-predicted but elusive gravitational waves left over from the birth of the universe. Unfortunately the waves may be more elusive than they realised, as further analysis showed that interstellar dust may have confused their results, and at the moment the discovery is still uncertain. But they’re getting there.

Thwaites Glacier, west Antarctica. One of the ice streams which have started to ‘collapse’, or pour their ice uncontrollably into the sea. Image courtesy NASA.

Still in the Antarctic, one of the biggest climate change stories was the discovery that the West Antarctic ice sheet, which has been very gradually declining since the end of the last ice age 10,000 years ago, has now passed a tipping point and will inevitably collapse whatever the climate does – raising global sea levels by around a metre – but that it will take several hundred years to do so.

First image returned from surface of Comet 67P, with foot of lander in foreground. Image courtesy ESA.

More cheerfully, 2014 saw the remarkable, decade-long Rosetta project culminate in the successful landing of a mini-science lab on a comet – from which it streamed back all kinds of measurements until its batteries died. The science results have already been impressive – we now know that organic molecules are plentiful there (it smells of vinegar and bad eggs), and that a long-mooted theory that comets are the source of water on Earth cannot be right if this comet is typical, because the water on the comet has a very different isotopic ratio to Earth’s water.

Zig-zag engravings on shell. Photo credit Wim Lustenhouwer, VU University Amsterdam.

We’re all familiar with cave drawings made by our ancestors and by Neanderthals, but the discovery of artistic carvings on an Indonesian sea-shell dated between 430,000 to 540,000 years turned out to have huge implications for those interested in human origins. The early date means that they must have been made by Homo erectus, a hominid precursor to our own Homo sapiens species – assigning ‘human’ behaviour to pre-humans.

The Illumina HiSeq X Ten. Image Courtesy Illumina Inc.

A technological advance means that it became possible this year to sequence a genome for less than $1000 – potentially opening the floodgates to all kinds of further discoveries. With this baby, you can sequence 18,000 genomes per year!

Jan-Nov 2014 was the warmest such period on record across the world’s land and ocean surfaces, with an average temperature that was 0.68°C (1.22°F) above the 20th century average. If December is at least 0.42°C (0.76°F) higher than its 20th century average, 2014 will surpass 2005 and 2010 as the warmest year on record. Image courtesy NOAA.

Not an auspicious end to the year, but a succession of ‘warmest ever’ months means that 2014 will almost certainly be the warmest year on record. In fact it’s been a year of bad news for climate scientists – a large part of Greenland has been found to be melting faster than thought, the rate of deforestation of the Amazon in 2013 was shown to have increased by more than 29%, and man-made CO2 emissions continue to track the high end of emission scenarios, eroding the chances of keeping global warming within 2C this century.

Well over a trillion tablets later, aspirin remains the biggest-selling drug ever created, and whilst it is no longer the recommended treatment for birth pain its uses have grown beyond just rheumatism to all kinds of ills, from hangover cure to reducing fevers and inflammation, preventing heart disease and stroke, and even reducing the incidence of various cancers – a wonder drug if there ever was one.

Felix Hoffmann started out his career as a pharmacist, but became so fascinated by the drugs he handled that he retrained as a chemist, getting a job as a research chemist with Bayer, Germany’s leading chemical company. Soon afterwards, and in the space of just two weeks, he synthesised both aspirin and heroin. He was not actually the discoverer of either drug, but he was the first to recognise the pain-relieving and fever-reducing properties of aspirin (initially by using his long-suffering father as a guinea-pig), and his employers were extremely quick to make it into a commercial success. Despite being arguably the most commercially successful synthetic chemist of all time, Hoffmann never received any royalties on his immensely valuable discoveries, although he had a long and profitable career with Bayer and eventually retired to live out his old age in Switzerland.

Pre-1904 Bayer advertisement for Aspirin and Heroin

Bayer aggressively marketed the drug and it became a commercial success within two years. Going from discovery to commercial production in such a short time would be impossible now, but in those days the head of the pharmaceutical department simply tested it for toxicity on himself, noticed no ill effects, and proceeded with trials on a ward-full of patients in a nearby hospital, before sanctioning production.

Interestingly the same easy-going approach to commercialisation was also applied to Hoffmann’s other discovery of the month, heroin. Heroin (actually acetylated morphine, discovered some 25 years previously by the English chemist C.R.A. Wright), was also commercialised by Bayer and marketed as a pain-relieving drug for childbirth and as a cough suppressant, of all things. It was not for some years until its extreme addictiveness was recognised, and it was almost 30 years before its use made illegal. It would be interesting to know which drug has proved most profitable over the years.

By patenting the synthesis of aspirin, Bayer had prevented others from manufacturing it, and so had a monopoly on the market. The first world war stopped the export of the drug from Germany, so the British Government offered a prize for anyone who could find a way of making it, since Bayer had also kept this secret. Within a year an Australian, George Nicholas, succeeded, naming his version ‘Aspro’; ironically, whilst Hoffmann did not benefit commercially, Nicholas did, to the tune of the £20,000 prize.

After the war, aspirin quickly became the world’s leading painkiller, and when Bayer’s patent expired in 1930, generic versions spread its use even wider. New uses of the drug were far from over though: in the late forties a Californian doctor named Laurence Craven noticed that it might be effective in reducing heart attacks, a suspicion confirmed by more extensive studies in the 1970s. Today, far more aspirin tablets are taken to prevent heart disease than to relieve pain.

In the last decade a number of studies have demonstrated that aspirin can also reduce the onset of various forms of cancer. It has been shown to reduce the likelihood of pancreatic cancer, and it has been estimated that regular use could prevent as many as 43 per cent of cases in women. Another study has shown that it can reduce the onset of polyps associated with colorectal cancer by a similar amount. Yet another recent study demonstrated that taking aspirin reduces the risk of contracting cancers of the mouth, throat and oesophagus by two-thirds.

Little could Herr Hoffmann Senior have foreseen the consequences of complaining to his chemist son about his rheumatism. And a good job he tried the aspirin and not the heroin.

The Rosetta project has been 21 years in the making and the probe itself has spent over ten years merely getting to comet 67P/Churyumov-Gerasimenko, culminating in some incredibly intricate and complicated manoeuvres to place the probe in orbit around the comet. The reason it’s so important is that comets are believed to be remnants from the dawn of the solar system, formed about 4 billion years ago, so by closely observing 67P we can see what comets and by inference the earliest planets were made of. But it’s a risky project – as the comet heats up either the lander or Rosetta or both could be knocked out by erupting jets of material. Closest approach to the sun will be on 15 August 2015 and the mission is due to run until December 2015, so armchair astronomers are in for an exciting year as the comet approaches the Sun.

The next date on the celestial calendar is April 2015 when NASA’s Dawn probe will visit the biggest asteroid, Ceres, almost half the size of Pluto. Dawn has already visited the second largest asteroid, Vesta, where it made the important discovery that there was water locked in minerals beneath the surface, and which appeared to periodically erupt outwards from pits up to 200 metres deep.

Comet 67P seen from Rosetta (ESA)

In July 2015 we reach what will perhaps be the celestial highlight of the year when the New Horizons probe flies past Pluto, hopefully avoiding the small crowd of satellites that have been discovered around Pluto in recent years. What will Pluto look like? And where will New Horizons go next? The plan is for a Kuiper Belt Object, but it depends a lot on what objects are within reach.

Then in July 2016, NASA’s Juno probe will reach and go into orbit around the gas giant Jupiter, the first craft to spend time at the planet since the NASA-ESA probe Cassini was there over a decade before. Juno will focus on investigating Jupiter’s composition, atmosphere and magnetic field, aiming to distinguish between prevailing theories of its formation in the solar system as well as to understand its internal dynamics better.

Montage of Juno probe and Jupiter (NASA)

We shouldn’t forget the veritable party going on at Mars though, with seven active missions in progress this year. On the surface, the Curiosity and Opportunity rovers are trundling around investigating its geology and looking for signs of past water, and above them are the Odyssey, Express and Reconnaissance orbiters, joined just last month by NASA’s MAVEN craft and the Indian Space Agency’s Mars Orbiter Mission (also known as Mangalyaan).

Mangalyaan in particular is a huge technical triumph, making India only the fourth country or country-group to have successfully sent a probe to Mars, and most remarkably doing so successfully at the first attempt, something that not even the US or Russia achieved. It is also the start of a minor flurry of missions next year by the newer space nations with China, India and Russia all planning to land probes on the Moon.

Further out the story gets even more interesting with not just India and China entering the planetary exploration game, but private enterprise too. In 2018 Inspiration Mars plans to launch two people on a 500 day return trip to Mars, and in 2023 Mars One aims to land the first human settlers on Mars. Now that really will be something to watch.

In fact, many of the familiar coastlines and estuaries of the world that we know have only existed for about 10,000 years. All the indications are that then, as now, about a third of the world’s population lived less than one hundred metres above the high-water mark, roughly the same amount by which sea levels rose at the end of the last ice age. Consequently many of the places our early ancestors lived are now inaccessible, submerged hundreds of feet beneath the waves – leaving large gaps in our knowledge of our past.

Investigating large areas of the sea bed on a scale fine enough to find human artifacts and settlements by traditional diving is an almost hopeless task. However, over the past decade, archaeologists have made enormous progress in developing other methods to uncover mankind’s history in areas now covered by the North Sea, the Arabian Gulf, and the Bering Strait, which were key population centres for our ancestors during the last ice age.

These discoveries are changing our understanding of our species’ development at a key period around 10,000 years ago when we started to become ‘civilised’, moving from hunter-gather lifestyles to begin to build and live in cities, supported by agriculture in fixed perennial locations. Here are a couple of examples.

Doggerland: the lost heart of Europe

One of the first submerged areas to be successfully investigated has been the southern North Sea between Britain and Europe. This large shallow area is known to fishermen as Dogger Bank, and trawlers have been bringing up Mesolithic artifacts up in their nets for around a hundred years – artifacts such as mammoth tusks, lumps of peat whose pollen indicates a woodland environment, and even antler points which have been worked by humans into harpoons – clear evidence that humans once lived there.

Fortunately, the area has been extensively surveyed by the oil industry, and archaeologists have been able to use the resulting seismic data to reveal the original land surface 10,000 to 8,000 years ago – now lying beneath about fifty metres of water and layers of sediment – and to map its rivers and valleys and even make 3D landscape models. Pollen samples from marine cores have then been used to add vegetation information to create a remarkably complete and vivid picture of this lost land, which archaeologists have now dubbed Doggerland.

Knowing better where to look, marine archaeologists have since dredged all kinds of man-made artifacts from the sea bed, giving an extensive picture of a human population who lived and hunted on Doggerland at the end of the ice age, what kind of animals they hunted and even their belief systems from artwork carved in bones and tusks. The people of Doggerland must have seen their island steadily shrinking as the ice sheets melted and sea levels rose, some gradually drifting away to drier lands – until one day it just wasn’t there at all.

The Garden of Eden: the ultimate archaeological site?

Arguably the place where humans have been most dramatically effected by past sea level rise has been the Arabian Gulf. Today`s Gulf is actually a very recent feature, only formed between 14,000 and 6,000 years ago by the same sea level rise that drowned Doggerland.

Prior to that, the Arabian Gulf Oasis, as it is usually referred to before the Gulf flooded, was a major human population centre for a very long time. When our ancestors first left Africa, one of their major exit routes was across the southern end of the Red Sea and southern Arabia, and then up into the Arabian Gulf Oasis. This fertile valley of over 250,000 sq km became a major population centre for humans for tens of thousands of years.

It was from here that our ancestors were to continue their global trek west into Europe, east to South East Asia and Australia, and north through Asia into Russia and China, from where they crossed the Bering land bridge into the Americas.

The Arabian Gulf Oasis is also the strongest candidate for a real-world location of the Garden of Eden, something that is supported by multiple evidence sources such as the description of rivers flowing through the Garden given in the Bible and the Quran, the locations where the legend was first recorded in ancient texts such as the Legend of Etana and the Epic of Gilgamesh, and the description of the flood in the Sumerian King List.

Human artifacts proving Mesolithic settlement have yet to be found beneath the Gulf in the same way as at Doggerland, but convincing evidence that it was once a regional centre of human development has come from another source. In 2010, Dr. Jeffrey Rose of the University of Birmingham mapped the occurrence around the Gulf of pottery and artifacts known as Ubaid style belonging to a relatively sophisticated people, all dated to around 8000 years ago. As Rose put it: ‘These settlements boasted well-built, perma¬nent stone houses, long-distance trade networks, elaborately decorated pottery, domesticated animals, and even evidence for one of the oldest boats in the world.’

The curious thing was, they were all found along the present day coastline of the Gulf, and they all appeared more or less out of nowhere, in areas with no previous history of fixed human settlement or those specific types of artifact. He concluded that the only explanation was that the people that made them had all come from a common origin, and that that origin had to be the Arabian Gulf Oasis. So the settlements and artifacts we find along the coast could only have been made by people from the Gulf.

The descendants of these Ubaid people went on to found the world’s first cities such as Ur and Uruk in present-day Iraq, invent writing, and develop civilizations. Marine archaeologists are now starting systematic sea bed searches for settlement remains similar to those found on land in an attempt to locate the earliest settlements in the Gulf Oasis.

In North America, another area of active research interest is the Bering land bridge between Alaska and Russia, which was a broad ice-free area during the ice age, and is now known to have been inhabited by humans for tens of thousands of years before rising sea levels engulfed it. Other signs of ice age human settlement have been found offshore Haida Gwaii on Canada’s west coast (the route which humans are believed to have taken as they migrated down into the Americas), and beneath Lake Huron stone structures for herding buffalo were recently discovered, built by the earliest First Nations people shortly after the ice sheets retreated.

Finally, these advances don’t merely fill in some of the blanks in our knowledge of our earliest human history. They also have a particular relevance for us today given concerns about the coming impact of rising sea levels caused by global warming; the difference is that back then humans were nomadic and could easily move to higher ground. With hundreds of millions of people living in large coastal cities with inflexible infrastructures, it will be much harder for us to adapt to such events in the future.

David Millar is a science writer with an interest in climate change past and present. He is the author of Beyond Dubai: Seeking Lost Cities in the Emirates which tells the tales of several Arabian lost cities abandoned through past climate change, as well as the story of man’s migration from the flooded Arabian Gulf Oasis towards surrounding lands to create the world’s first civilizations.

But earlier this month, the US Government released its latest National Climate Assessment, documenting numerous changes to the climate of the United States that are already happening in every region of the country and affecting several key industries.

It’s an impressive document and so it should be – more than three hundred scientists and sixty Federal advisors have labored on it for four years. It weighs in at over 800 pages and documents numerous recent changes to the American climate – including more frequent heavy precipitation events in the north-east, increased levels of drought, water stress and wildfires in the south-west, and more marine acidification in the Pacific north-west.

Having said that, it’s not all doom and gloom. Surprisingly positive progress has been made in the underlying problem of reducing CO2 emissions in the US – in fact, between 2008 and 2012, carbon dioxide emissions were reduced by almost ten per cent, mostly by moving more electricity production from coal-fired to gas-fired power stations. In some places a warmer climate has actually resulted in higher crop yields, thanks to the longer growing season.

But the good news is definitely outweighed by the negative impacts, and what is most noticeable is that many of these impacts are no longer mild inconveniences; they are starting to affect people’s lives quite directly as well as the economy. Increased acidification has already impacted shellfish hatcheries and caused some to close down. Corn producers in Iowa, oyster growers in Washington State, and maple syrup producers in Vermont have all experienced climate-related changes outside of the normal bounds. And of course, more frequent extreme weather is something that’s been particularly noticeable to all of us the past few years – longer and hotter summers, more severe rainstorms and hurricanes, less sea-ice off Alaska leading to greater coastal erosion.

What is also quite striking is the tone of the report: it speaks less about reversing global warming and much more about mitigating the effects – and above all about adaptation to the inevitable. At long last it reads like an admission that if you’re hurtling towards a concrete wall in your Ferrari, then merely taking your foot off the gas won’t avoid a calamity, only that it might make the impact marginally more survivable.

Highlighting this inevitability, the report specifically admits that ‘because of past emissions … some additional climate change and related impacts are now unavoidable’. Even under an optimistic scenario of an immediate ‘significant reduction’ in greenhouse gas emissions their estimate is that global temperatures will continue to increase another 1.9˚F (1.1 C) by the end of the century, thereby doubling the change witnessed already.

What ‘adaptation’ might mean in reality is harder to pin down. They suggest building more bike lanes, planting the roofs of buildings with grass to absorb CO2, building houses near the coast on stilts to allow storm surges to pass underneath, and even updating city building codes to better protect against insects carrying dengue fever (higher temperatures will inevitably mean more diseases).

State adaptation plans are not much better: in Florida, they passed a law limiting usage of water for their lawns, and in Montana they will set up a climate change website. Only Maine seems to have a pragmatic approach – they will require future coastal buildings to be set back from the future shoreline position, based on a projected two foot rise in sea level.

The authors say that they hope their report will provide ammunition for President Obama and Congress to take action. There is certainly room for that. One of the most revealing maps in the entire report is a colour-coded map of the US showing status of climate adaptation plans by state. Apart from the coastal states, the entire map is blank.

David Millar is a science writer with an interest in climate change past and present.