The year 2018 was a great occasion to chew if you're interested in science and the environment. It was a memorable year, from the climate scientists' glaring warning about the danger of temperatures rising above 1.5 ° C to the discovery of a 20 km wide liquid-water lake on Mars.
Here is an overview of some of the most beautiful eyes of 2018. Catch stories.
A "safe" limit to warming
The rise in global temperatures by 2 ° C by the end of this century has long been considered a gateway to dangerous climate change. Researchers had argued that it was necessary to stay within those limits to avoid the most damaging effects of global warming.
However, some have opted for an even lower target of 1
This would result in millions of fewer people losing their homes to rising seas, fewer species threatened with extinction and a drastic reduction in the number of people suffering from water scarcity.
But it would also be very expensive and would require "rapid, far-reaching and unprecedented changes" in society. The report did not tell governments what to do, but presented a number of approaches, including strong savings in greenhouse gas emissions, a rapid transition to renewables, and lifestyle and dietary changes.
Other climate stories from 2018
The first animals
The more than one million species of animals that still live today are amazingly diverse, from the vast blue ocean whale to the rough ones Earthworms under our feet. However, their early development of unicellular ancestors remains a mystery.
In the hunt for the earliest animal life, more attention was paid to a group of enigmatic life forms known as "Ediacaran biota" 500 million years ago. These were some of the first complex organisms that appeared on Earth.
But their position on the tree of life is hard to decipher. These strange creatures have variously been categorized as lichens, mushrooms, and even as halfway between plants and animals.
In September, scientists were able to extract cholesterol molecules from a fossilized Ediacaran life form Dickinsonia that resembled a flat jellyfish. Cholesterol is one of the molecular hallmarks of animal life and clearly shows that the Ediacaran biota are animals.
Other paleontological stories from 2018
The global plastic garbage crisis was one of the biggest global issues of 2018. The problem was posed by Blue, introduced by David Attenborough The BBC's Planet 2 series featured shocking shots of the destruction of oceans and marine life through our plastic addiction.
David Shukman, science editor, visited Indonesia to report on a swamp of plastic garbage that had clogged rivers and canals in Bandung on the Indonesian island of Java. The crisis was so acute that the army was called in to clean up a huge pile of plastic bottles, bags and other plastic wrappers.
The problem only seems to get worse. In March, a report commissioned by the UK government suggested that the amount of plastic in the sea could triple in a decade if the waste is not contained.
Further plastic garbage stories from 2018
- Antiplastic focus "dangerous distraction"
Ghost Particle Buster
Neutrinos are some of the basic building blocks of the universe. These subatomic particles move more or less freely around the cosmos and interact with very little. It is estimated that a single neutrino particle can go through one light year (about 10 trillion km) of lead without hitting a single atom.
Many neutrinos that we encounter on Earth come from the sun or the Earth's atmosphere. However, the origins of a group of ultra-high neutrinos remained mysterious until this year. In July, an international team traced one of them for a distant galaxy that fired a particle beam directly at the Earth.
This type of galaxy is called Blazar. It has an extremely bright core, which is caused by the energy of its central, massive black hole. When matter falls into the hole, huge jets of charged particles are created, turning these galaxies into huge particle accelerators.
The IceCube experiment in the Antarctic has been collecting data on these ultra-high energy neutrinos for six years. But this was the case For the first time, researchers were able to match it to a source in the sky.
More astronomy stories from 2018
A watery Martian and Moon
We know that there is water in the form of ice on Mars, which is a sign of occasional fluid flows. In July, a team of scientists reported the discovery of a 20 km wide lake located under the planet's south polar ice cap.
Nasa's Curiosity Rover explores the remains of an ancient seabed, but this is the first sign of stubborn waters today. The result was exciting because scientists have long searched for signs of today's liquid water on Mars.
"We are no closer to recognizing life," said Manish Patel of the Open University in the UK Let us know where we should look to Mars. "
Mars was not the only cosmic body to make headlines in water, and in August researchers published the most conclusive evidence of ice on the Moon's surface.
Data from the Indian Chandrayaan-1 spacecraft point to icy deposits on the north This ancient water could be used as a resource for future human missions to the Moon.
More planetary science stories from 2018
What happened to the Stonehenge builders?
The field of ancient DNA – the extraction and analysis of genetic material from long-dead people – has given us unprecedented insights into the past. A remarkable result from 2018 was the discovery that the ancient people of Great Britain were almost completely replaced by the continent some 4,500 years ago in a mass migration.
The Neolithic British had just built the big stones in Stonehenge when they were overrun by newcomers known as the beaker people. As a result, 90% of the British gene pool was replaced in just a few hundred years. Why this happened is unknown. But illness, hunger and conflict are all possible candidates.
In another 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 various species of humans that inhabited Eurasia before our species – Homo sapiens – left Africa.
Other ancient DNA stories from 2018
- The early Briton had dark skin and blue skin eyes
- DNA illuminated settlement in the Pacific
In November, scientists identified a large impact crater under Greenland ice. The 31-km-wide depression emerged as the scientists studied radar images of the island's rocky terrain.
The shell was probably excavated by a 1.5 km wide iron asteroid about 12,000 to three million years ago. Some researchers have doubts about the evidence presented so far. However, it has created some fascinating opportunities, including a potential link to a period of intense cooling that permeated the global warming that Earth experienced as the culmination of the last Ice Age.
There is a long-standing hypothesis that this temperature dip could be the result of the sun's rays being blocked by debris thrown into the atmosphere by an impact, and the smoke and ashes of forest fires resulting therefrom solved. If further work confirms that the age of the crater is near the bottom of the age group, this could spark interest in this old debate.
Further Earth Science Stories from 2018:
- East Antarctica Glacier
- How Greenland Burned Its Bottom
A Former Exodus
Several lines of evidence indicate that the ancestors of most of the people living outside of Africa left the continent 60,000 years ago in a migration. There is evidence, however, that the pioneer of modern man ( Homo sapiens ) has made attacks outside of Africa before that time.
In January, scientists uncovered the jawbone of a modern human who died in Israel 185,000 years ago, thousands of years earlier than previous evidence. Assumed wisdom suggests that these earlier excursions have not given a lasting footing to the modern man in Eurasia.
The jawbone, however, fits in with the emerging image of earlier emigration outside of Africa, which continues to spread in Eurasia as many believed. These pioneers seem to have lived alongside other human species such as the Neanderthals and Denisovans. However, it remains a mystery why their genetic signatures are not preserved in people living today.
Other Human Development Stories from 2018
Rocks from Mars
After years of discussion and a false start, the European and American space agencies made their first significant move to bring stones back from Mars.
In April, NASA and Esa signed a memorandum of understanding that would lead to the first "round trip" to another planet.
The project would allow scientists to access key questions about the history of Mars, including whether the planet once harbored life. However, it would also allow geologists to build an accurate chronology for events in the history of the Martians.
US missions in recent decades have contributed enormously to our understanding of the Red Planet in situ but there are mass limitations on the experiments that may fit on a payload dedicated to Mars.
There is no comparison to the information that scientists can gather from the study of rock and soil using scientific instruments in terrestrial laboratories.
Further space exploration stories from 2018
Plastic in our water  Copyright of the pictures
Plastic waste is becoming more common in our daily lives, and this extends to our drinking water as well. Research by the journalist organization Orb Media has shown that an average of 10 plastic particles per liter are produced in large bottled water brands.
In the largest study of its kind, 250 bottles were purchased in nine different countries. Almost all contained tiny plastic particles.
The north of our planet is often considered a pristine wilderness. However, this year researchers expressed concern about the high concentration of plastic in the Arctic sea ice.
It was found that the number of particles in one liter of molten Arctic sea ice was higher than in the open ocean. The scientists said it needed further research on how zooplankton, invertebrates, fish, seabirds and mammals work.
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