The year 2018 provided a lot to chew if you are interested in science and the environment. From the glaring warning from climate scientists about the dangers of letting the temperature rise beyond 1.5 ° C until a 20-km liquid water lake was discovered on Mars, it was a memorable year.
Here is a summary of some of the most compelling stories of 2018.
A "safe" limit for heating
An increase in global temperatures of 2C by the end of this century has been seen as the gateway to dangerous climate change. The researchers argued that maintaining this limit was necessary to avoid the more damaging effects of global warming.
But some have pressed for an even smaller target of 1.5C. In October, climate scientists released a large report detailing what would be involved in keeping the temperature rising within that most difficult limit.
That would result in millions of people losing their homes to rising seas, fewer endangered species and a drastic reduction in the number of people suffering from water shortages.
But it would also be extremely expensive and would require "rapid, far-reaching and unprecedented changes" for society. The report did not tell governments what to do, but set a number of approaches, including heavy cuts in greenhouse gas emissions, a rapid transition to renewable energy, and lifestyle and dietary changes.
Other Climate Change Stories of 2018
The first animals
The more than a million species of animals nowadays are incredibly diverse, from the gigantic blue oceanic whale to the tiny earthworms beneath our feet. But its initial evolution of unicellular ancestors remains shrouded in mystery.
In the quest for the earliest animal life, much attention has been focused on a group of enigmatic life forms – known as the "biota ediacarana" – of more than 500 million years ago. These were some of the first complex organisms to appear on Earth.
But their position on the tree of life is difficult to decipher. These curious creatures have been categorized as lichens, fungi and even as a middle house between plants and animals.
In September, scientists were able to extract cholesterol molecules from an ediacarana fossilized life form called Dickinsonia, which resembled a flat living water. Cholesterol is one of the molecular marks of animal life, clearly demonstrating that the Ediacaran biota was an animal.
Other stories from paleontology of 2018
Giant plastic & berg
The global plastic waste crisis was one of the big issues of 2018. The problem was highlighted by the BBC's Blue Planet 2 series by David Attenborough, which contained shocking images of the devastation caused by the oceans and marine life by our plastic addiction.
In April, our science editor, David Shukman, visited Indonesia to report a tangle of plastic waste that clog rivers and canals in Bandung on the Indonesian island of Java. The crisis was so acute that the army was called in to help clean a vast bergelim of bottles, bags and other plastic packaging.
Worryingly, the problem only seems to get worse. In March, a report commissioned by the UK government suggested that the amount of plastic in the ocean could triple in a decade unless litter is contained.
Other Stories of Plastic Waste from 2018
- Plastic picking heads for cleaning the ocean
- Focus anti-plastic & dangerous distraction & # 39;
Phantom Particle Busters
Neutrinos are some of the fundamental blocks of the Universe. These subatomic particles move around the more or less unimpeded cosmos, interacting with very little. In fact, it is estimated that a single neutrino particle can pass through a light-year (about 10 trillion km) of lead without reaching a single atom.
Many neutrinos we encounter on Earth come from the Sun or the Earth's atmosphere. But the origins of a group of ultra-high energy neutrinos remained mysterious until this year. In July, an international team located one of them in a distant galaxy, firing a "beam" of particles directly on Earth.
This type of galaxy is called blazar. It has an intensely bright nucleus caused by the energy of its huge central black hole. As matter falls into the hole, huge jets of charged particles emerge, transforming these galaxies into vast accelerators of particles.
The IceCube experiment in Antarctica has collected data on these ultra-high energy neutrinos for six years, but this was the first time researchers have been able to combine them with a fountain in the sky.
Other Astronomy Stories of 2018
A watery Mars – and Moon
We know that there is water on Mars in the form of ice, and there are potential signs of occasional liquid leaks. But in July, a team of scientists reported the discovery of a 20-kilometer wide lake under the polar ice cap of the planet.
NASA's Curiosity rover has explored the remaining rocks of an ancient lake bed, but this is the first sign of a lingering body of water today. The result was exciting because scientists have long hunt for signs of current liquid water on Mars.
"We're no closer to actually detecting life," said Manish Patel of the UK Open University, "but what this finding does is give us the location to look for on Mars."
Mars was not the only cosmic body making headlines. In August, researchers published what they said was the most definitive proof of ice on the moon's surface.
Data from the Chandrayaan-1 probe from India suggest the presence of ice deposits on the north and south poles. This ancient water may be accessible as a resource for future human missions to the Moon.
Other Planetary Science Stories of 2018
What happened to the Stonehenge builders?
The field of ancient DNA – which involves the extraction and analysis of genetic material from people long dead – has provided us with unprecedented insight into the past. An astonishing result since 2018 was the discovery that the ancient peoples of Britain were almost completely replaced in a mass migration of the continent some 4,500 years ago.
The Neolithic Britons had just erected the great stones at Stonehenge when they were invaded by newcomers known as the staff of the Bowls. This has resulted in 90% of the British gene pool being replaced in just a few hundred years. Why this happened is unknown. But illness, hunger and conflict are potential candidates.
In a different study published in 2018, researchers have shown that 50,000-year-old bone fragments from Russia belonged to a girl who was half Denisovan and half Neanderthal. The Denisovans and Neanderthals were distinct species of humans that inhabited Eurasia before our species – Homo sapiens – He left Africa.
Other old DNA stories of 2018
- The first Breton had dark skin and blue eyes.
- DNA Sheds Light on Pacific Colonization
In November, scientists identified what appeared to be a large impact crater under the Greenland ice. The 31-kilometer wide depression came to the surface as scientists examined radar images of the island's rocky bed.
The cup was probably excavated by an iron asteroid 1,5 km wide, between about 12,000 and 3 million years ago. Some researchers have doubts about the evidence presented so far. But that raised some intriguing possibilities, including a potential connection to a period of strong cooling that punctuated global warming as the Earth emerged from the height of the last Ice Age.
There is an old hypothesis that this drop in temperatures could have been the result of the sun's rays being blocked by debris thrown into the atmosphere by an impact and the smoke and ashes from the forest fires it caused. If additional work confirms that the age of the crater is near the lower end of the age range, it may rekindle interest in that old debate.
Other Earth Science Stories Beginning in 2018:
- East Antarctica glaciers are stirring
- How Greenland has devastated its bottom
An earlier exodus
Multiple lines of evidence suggest that the ancestors of most humans living outside Africa left the continent in a migration of 60,000 years ago. But there is some evidence that modern human pioneers (Homo sapiens) made inroads out of Africa before this time.
In January, scientists uncovered the jawbone of a modern human who died in Israel 185,000 years ago, tens of thousands of years before earlier evidence. The wisdom received suggests that these earlier excursions failed to provide modern humans with a permanent position in Eurasia.
But the jawbone fits with the emerging image of earlier migrations from Africa that spread even more to Eurasia than many believed. These pioneers seem to have lived alongside other human species, such as the Neanderthals and the Denisovans. But it remains a mystery as to why its genetic signatures are not preserved in living people today.
Other Human Evolution Stories of 2018
After years of discussion and a false start, European and American space agencies took their first significant step toward bringing back Mars rocks.
In April, NASA and Esa signed a letter of intent that would lead to the first "round trip" to another planet.
The venture would allow scientists to begin answering key questions about Martian history, including whether the planet has ever lived. But it would also allow geologists to begin building a precise chronology for events in Martian history.
US missions over the past decades have contributed enormously to our understanding of the Red Planet on site, but there are mass restrictions on experiments that can fit into a payload destined for Mars.
There is no comparison with the information that scientists can get when studying Martian rocks and soil with the scientific instruments available in the ground laboratories.
Other Space Exploration Stories of 2018
Plastic in our water
Plastic waste is increasingly present in our daily lives, and this extends to our drinking water. Research by journalism organization Orb Media found an average of 10 plastic particles per liter in the main brands of bottled water.
In the largest investigation of the genre, 250 bottles purchased in nine different countries were examined. Almost all contained tiny plastic particles.
The northern tip of our planet is often regarded as an untouched wilderness. But this year, the researchers expressed concern about the large concentrations of plastic accumulated in the Arctic sea ice.
The number of particles in just one liter of molten Arctic sea ice was greater than in the open ocean. The scientists said there is a need for further research into its effects on zooplankton, invertebrates, fish, seabirds and mammals.
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