The Australian Science Media Centre presents the top 10 science stories of 2019…
Australia’s 2019 fire season arrived early with devastating effect, beginning with bushfires in QLD in September, followed by unprecedented November blazes which ripped through NSW and QLD, as well as smaller flare-ups in several other states.
Hundreds of properties have already been lost and six people have died in the fires, which are beginning to encroach on Sydney. Conditions are expected to worsen as summer heats up. Scientists said that, while it’s hard to be sure individual fires were caused by climate change, we can expect to see longer and more intense fire seasons in Australia as a result of global warming.
And it wasn’t just Australia feeling the heat this year. News that Amazon rainforest fires were so vast they could be seen from space caused uproar around the world in August – development and deforestation were the prime suspects.
Dramatic fires also ravaged California, burning around 100,000 hectares and killing five, while Alberta in Canada lost around 800,000 hectares to wildfires earlier in the year.
Scientists achieved a feat once thought impossible in April, capturing an image of a black hole at the centre of a galaxy called Messier 87, 53 million light-years away. The image shows a radiant halo of hot, glowing gases flowing into the black hole, which is itself completely black.
At 40 billion km across, it is three million times the size of the Earth, and larger than our entire Solar System. The team used a network of eight telescopes known as Event Horizon to produce the image, at a total cost of around $75m.
Their next project is to produce an image of the supermassive black hole at the centre of our own galaxy, the Milky Way. Although it’s closer, imaging our local black hole will be harder, the team said, because the ‘ring of fire’ around the Milky Way’s black hole is smaller and dimmer.
A mind-reading exoskeleton helped a paralysed man walk again
A tetraplegic French man known simply as Thibault – his surname remains private – described feeling like the “first man on the Moon” when he was able to move all four of his paralysed limbs again with the aid of a robotic exoskeleton that can read his thoughts.
Thibault, who is paralysed from the neck down following a 15m fall, had recording devices implanted into the area of the brain that controls sensation and movement that were designed to pick up and transmit signals.
He then spent two years training an artificial intelligence to understand his thoughts by controlling a virtual avatar on a screen, and he gradually learned to make the exoskeleton walk and reach out to touch objects.
The exoskeleton has 14 joints, and Thibault was able to complete tasks that involved controlling eight of those successfully more than two thirds of the time. However, the researchers said an exoskeleton like this is unlikely to be available to the public any time soon.
At the moment, the suit has to be suspended from the ceiling, so it can only be used in the lab, and Thibault’s movements, particularly walking, are far from perfect.
This year we learned that the last five years were the hottest on record, that July 2019 was the hottest month ever recorded, that carbon dioxide in the atmosphere had reached new all-time highs, that Earth hasn’t warmed this fast for at least the last 2,000 years, and that global sea levels are likely to continue to rise for the rest of this century, even if we take robust action to curb greenhouse gas emissions now.
In response, more than 11,000 scientists declared a climate emergency in November, although a few of the signatories of that declaration turned out to be fake. Faced with such dire news, children around the world joined school strikes inspired by Swedish teenager Greta Thunberg, whose original solitary strike spawned a global movement.
Thunberg has become the modern face of the movement to spur meaningful action on climate change, and has vigorously urged world leaders to move beyond words towards more concrete action.
In October, Australian researchers announced they’d pinpointed the location of the ancestral home of anatomically-modern humans, and singled out an area in southern Africa, south of the Zambezi River, in what is now an inhospitable part of Botswana, Namibia and Zimbabwe.
The team came to their conclusions by looking at the genetic code of mitochondria – the cell’s ‘energy factories’ – from 1,000 living southern Africans, combined with linguistic, cultural, historical, geographic and archaeological data.
Mitochondrial DNA is inherited from our mothers, so ancestry can be tracked back in time to 200,000 years ago, when the team believes modern humans originated. At that time, the area was home to a huge lake, and modern humans may have lived there for 70,000 years before venturing out to dominate the rest of the planet, the researchers said.
So, had they really found our ‘Garden of Eden’? Not all experts were convinced, as many believe there was no single point of origin for modern humans, while others accused the authors of ignoring archaeological evidence that points to an earlier origin for modern humans around 300,000 years ago.
In January, all eyes were on Australia as the media beamed shocking images of millions of dead fish in the Darling River around the world, raising domestic concerns about water management in the Murray-Darling Basin. So, what caused the mass fish die-off?
Scientists said large numbers of fish became trapped in smaller pools as drought shrank the river system. A hot summer meant algal blooms thrived in these pools, leading to very low levels of oxygen in the water at the riverbed, effectively trapping the fish in the upper layers of the water.
When the weather cooled, combined with strong winds, the low-oxygen water mixed with the upper layers, and meant the fish no longer had enough oxygen to breathe, leading millions to suffocate. Later that month, the findings of the Murray-Darling Basin Royal Commission were released, calling for a 15% reduction in water removed from the river system for agriculture.
Then, in February, a report by the Australian Academy of Science pointed to “serious deficiencies in governance and management”. In April, the Federal Government released its own report into the fish deaths, and its plan to prevent future events was published in October, although many experts felt it did not go far enough, and that further mass fish die-offs remain likely.
China made history in January when it announced its Chang’e 4 craft had achieved the first ever soft landing on the Moon’s dark side.
Reaching the far side of the Moon is a challenge because relaying signals round it to control landers is tough. Although we have maps of the surface created by orbiting probes, nobody had successfully touched-down there before this year.
Chang’e 4 relayed back images via satellite, showing craters at the landing site, and the successful deployment of its rover, Yutu-2, sent to explore the Moon’s Von Karman crater. Chang’e 4 is packed with scientific experiments, including an attempt to start a biosphere – an artificial, self-sustaining environment – based on fruit flies, canola, cotton, cress, potatoes and yeast. Those seeds provided China with another historic first when Chang’e 4 relayed back images of the first ever plant to sprout on the moon a few days after landing.
One of the cotton plants had germinated and grown two small leaves. Sadly, around a week later, China announced that the plant had fallen victim to the harsh cold of the lunar night and died.
In November, a US veteran using the pseudonym Ray who had lost his legs, penis and scrotum when caught in the blast of an improvised explosive device (IED) reported “feeling whole again” thanks to a successful organ transplant.
Initially, Ray was unwilling to reveal the injuries to his genitalia, but the surgery, which involved transplanting a penis, scrotum, and part of an abdominal wall, has left him able to urinate normally, achieve erections and even orgasm. Ray’s was only the fourth penis transplant, and the first of both penis and scrotum, ever attempted, a gruelling procedure which took 35 doctors 14 hours to complete.
It’s a notoriously tricky surgery to perform, as grafting the donor penis involves stitching together blood vessels and nerves that are only millimetres wide. Ray will probably have to take anti-rejection drugs for the rest of his life, which means health risks, but said agreeing to the transplant was “one of the best decisions I ever made”.
2019 was the year we started to face up to our plastic problem, as we realised the scale it had reached, and several countries moved to ban single-use plastics, with a focus on straws and bags. Scientists studying microplastics, tiny particles less than five millimetres long which form as larger pieces of plastic break down, found them everywhere they looked.
Scientists estimate we’re each consuming an average of more than 74,000 microplastic particles every year – the equivalent of eating a credit card every week – and it’s still unclear whether all those microplastics pose a risk to human health.
It was the comeback nobody wanted to see as serious measles outbreaks cropped up around the world throughout 2019. Measles cases have increased by roughly ten times in Africa, doubled In Europe, and tripled in the western Pacific region this year.
A recent outbreak in Samoa has been so serious, causing at least 70 deaths, mainly of young children, that the country temporarily shut down its government.
Comparatively, Australia has remained better off so far, although confirmed measles cases have nearly doubled here since 2018. But our neighbours in New Zealand have been hit hard – measles has rocketed there by more than 46 times since 2018, with 1,666 confirmed cases so far in 2019.
The resurgence of the disease in the western world has been fuelled, at least in part, by parents refusing to vaccinate their kids, scared by stories of vaccines causing autism. Meanwhile, many in the developing world still do not have access to vaccines.