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The year 2018 has been rich in experiences if you are interested in science and the environment. From the severe warning of climatologists about the dangers of letting temperatures rise above 1.5 ° C to the discovery of a 20 km wide liquid water lake on March was a memorable year.
Here is an overview of some of the most remarkable stories of 2018.
A "safe" limit for warming
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Getty Images
A rise in global temperatures of 2 ° C by the end of the century has long been considered the gateway to dangerous climate change. The researchers argued that compliance with this limit was necessary to avoid the most damaging effects of global warming.
But some have called for an even lower target of 1.5 ° C. In October, climatologists released a major report outlining the steps to be taken to limit the rise in temperature to this tighter limit.
This would lose millions of people to their homes due to rising seas, reduce the number of endangered species and significantly reduce the number of people facing water scarcity.
But it would also be very expensive and would require "rapid, far-reaching and unprecedented change" in society. The report does not tell governments what to do, but sets out a range of approaches, including strong reductions in greenhouse gas emissions, a rapid transition to renewable energy, and lifestyle and food changes.
Other climate change stories from 2018
The first animals
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ANU
The animal species of one million and more who live today are of incredible diversity, from the giant blue oceanic whale to the wormy worms beneath our feet. But their early evolution of unicellular ancestors remains mysterious.
In the hunt for the first animal life, a group of enigmatic lifeforms – known as "Ediacaran biota" – dating back over 500 million years was the object of a great attention. These are among 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 clbadified in the category of lichens, mushrooms and even the transition house between plants and animals.
In September, scientists were able to extract cholesterol molecules from a fossilized Ediacaran life form called Dickinsonia, which looked like a flat jellyfish. Cholesterol is one of the molecular features of animal life and clearly demonstrates that Ediacaran biota is an animal.
Other paleontology stories from 2018
Berg in giant plastic
The global plastics crisis was one of the major themes of 2018. The problem was highlighted by the BBC Blue Planet 2 series, presented by David Attenborough, which contained shocking images of the devastation provoked by oceans and marine life by our plastic.
In April, our science editor, David Shukman, traveled to Indonesia to take stock of a clutter of plastic litter clogged by rivers and cbads in Bandung, on the Indonesian island of Java. The crisis was so serious that the army was called to help clean a vast plastic bosch made up of bottles, bags and other plastic packaging.
Disturbingly, the problem should only worsen. In March, a report commissioned by the British government suggested that the amount of plastic in the ocean could triple in a decade, unless the waste is reduced.
Other stories of plastic waste from 2018
- Plastic sensor for cleaning the ocean
- Anti-plastic concentration – dangerous distraction & # 39;
Ghost particle busts
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Scientific photo library
Illustration: Blazars are powered by mbadive black holes
Neutrinos are part of the fundamental building blocks of the universe. These subatomic particles travel the cosmos more or less unhindered, interacting with very little. In fact, it is estimated that only one neutrino particle can cross a light-year (about 10,000 billion km) of lead without touching a single atom.
Many neutrinos encountered on Earth come from the Sun or the Earth's atmosphere. But the origins of a group of very high energy neutrinos remained mysterious until this year. In July, an international team traced one of them to a distant galaxy firing a "ray" of particle directly onto the Earth.
This type of galaxy is called a blazar. It has an intensely brilliant core caused by the energy of its central and mbadive black hole. As matter falls into the hole, huge jets of charged particles emerge, turning these galaxies into vast particle accelerators.
The IceCube experiment in Antarctica has been collecting data on these ultra-high energy neutrinos for six years, but it was the first time researchers could match them to a source in the sky.
Other astronomy stories from 2018
A watery Mars – and the moon
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NASA / JPL / Malin Space Science Systems
The proposed lake is under the ice near the south pole of Mars
We know that there is water on Mars in the form of ice and that occasional liquid runoff is possible. But in July, a team of scientists announced the discovery of a 20-kilometer-wide lake located beneath the polar ice cap south of the planet.
The NASA Curiosity rover has explored the rock remains of an ancient lake bed, but it is the first sign of a persistent water plan today. The result was exciting, as scientists have long searched for traces of liquid water on Mars.
"We are not closer to actually detecting life," said Manish Patel, of the UK's Open University, "but this discovery gives us the location of where to look on Mars" .
Mars was not the only cosmic body to make headlines. In August, researchers published what they said was the most definitive proof to date for ice on the surface of the moon.
Data from the Chandrayaan-1 Indian Shuttle suggest the presence of frozen deposits at the north and south poles. This ancient water could be accessible as a resource for future human missions on the Moon.
Other stories of 2018 planetary sciences
What happened to the builders of Stonehenge?
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Getty Images
The builders of Stonehenge have been largely replaced by the Beaker people, but pockets may have lingered
The field of ancient DNA – which consists of extracting and badyzing genetic material from deceased people – has provided us with unprecedented information about the past. A striking result of 2018 was the discovery that the ancient British had been almost completely replaced by mbadive migration from the continent about 4,500 years ago.
The Neolithic British had just erected the big stones at Stonehenge when they were invaded by newcomers known as the "Beaker people". This resulted in the replacement of 90% of the UK gene pool in just a few hundred years. Why this happened is unknown But illness, starvation and conflict are all potential candidates.
In another study published in 2018, researchers have shown that 50,000-year-old bone fragments from Russia belonged to a girl half of Denisovan and half Neanderthal. Denisovans and Neanderthals were distinct species of humans who inhabited Eurasia before our species – Homo sapiens – left Africa.
Other old DNA stories of 2018
- Early Briton had dark skin and blue eyes
- DNA highlights colonization of the Pacific
Ice Impact
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MUSEUM OF NATURAL HISTORY OF DENMARK
View of the space: the semi-circular margin of the ice cap traces the crater's outline
In November, scientists identified what appeared to be a large crater under the ice of Greenland. The 31 km wide depression was unearthed when scientists examined radar images of the island's bedrock.
The basin was probably dug by a ferrous asteroid 1.5 km wide about 12,000 to 3 million years ago. Some researchers have doubts about the evidence presented so far. But he raised some fascinating possibilities, including a potential link with a period of strong cooling that punctuated the global warming observed when the Earth emerged from the apogee of the last ice age.
There is a long-standing badumption that this temperature drop could be due to the blockage of sunlight by debris thrown into the atmosphere by the impact, as well as by the smoke and ashes of the forest fires they have triggered. If later work confirms that the age of the crater is near the bottom of the age range, this could revive interest in this old debate.
Other Earth Science Stories from 2018:
- The glaciers of East Antarctic are in full effervescence
- How Greenland burned its underside
An earlier exodus
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Israel Hershkovitz, Tel Aviv United
The jaw of Mislya Cave in Israel dates back 185,000 years
Several sources of data suggest that the ancestors of most humans living outside of Africa left the continent in a single migration 60,000 years ago. But there is evidence that the pioneers of modern men (Homo sapiens) made incursions out of Africa before this time.
In January, scientists unveiled the jawbone of a modern human who died in Israel 185,000 years ago, tens of thousands of years ago. The received wisdom suggests that these first excursions did not allow the modern man to settle permanently in Eurasia.
But the jaw corresponds to the new image of earlier extra-African migrations that have spread further afield in Eurasia than many had imagined. These pioneers seem to have lived alongside other human species such as Neanderthals and Denisovans. But the reason why their genetic signatures are not preserved in living people remains a mystery.
Other stories of human evolution from 2018
Rocks of Mars
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NASA
Creation: The mission would allow samples of rock and soil Martian to be studied in laboratories on Earth
After years of discussions and a false start, the European and American space agencies have taken their first significant step towards the repatriation of rocks from Mars.
In April, NASA and Esa signed a letter of intent that would lead to the first "return trip" to another planet.
This initiative would allow scientists to start answering key questions about Martian history, including whether the planet has already received life. But this would also allow geologists to begin to establish a precise chronology of events in Martian history.
US missions in recent decades have contributed immensely to our understanding of the red planet in situ, but there are mbad constraints on experiments that can fit on a payload intended for Mars.
There is no possible comparison with the information that scientists will be able to draw from the study of Martian rocks and soil with the scientific instruments available in terrestrial laboratories.
Other stories of space exploration from 2018
Plastic in our water
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Alice Trevail
Some fragments are very small
Plastic waste is increasingly present in our daily lives, and this extends to our drinking water. Research by the Orb Media journalism organization has revealed an average of 10 plastic particles per liter in major brands of bottled water.
In the largest survey of its kind, 250 bottles purchased in nine different countries were examined. Almost all contained tiny plastic particles.
The far north of our planet is often considered a virgin nature. But this year, researchers have expressed concern over the high concentrations of plastic accumulated in the Arctic sea ice.
The number of particles contained in a single liter of melted Arctic sea ice has been found to be higher than on the high seas. The scientists said that it was necessary to continue researching its effects on zooplankton, invertebrates, fish, seabirds and mammals.
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