13 of the coolest scientific discoveries of the year

Over their long lives, whales accumulate earwax plugs that can get as long as ten inches in large species.

The plugs show bands that correspond with their age – every year, they have heavy feeding times and migration times that change the color of the wax.

In a report published in the journal Nature Communications in November, researchers described how they studied the chemical make-up of the bands and discovered that the whales produced significantly more of the stress hormone cortisol during years when the most whales were being hunted (the early 20th century and the 1960s), as well as during World War II, when whaling was low but submarines, battleships, and depth charges were common.

Cortisol levels have been steadily rising in recent decades too, despite the fact that whaling has been uncommon since the 1970s hunting moratoriums were put in place.

Warming sea temperatures appear to be creating stress for the marine mammals, scientists told the Atlantic.

Feeling stressed? Don’t go digging in your ears – here’s 17 steps you can take to lower your blood pressure.

This past summer, a report in Science revealed that radar scans from the Mars Express spacecraft had detected an underground lake on the red planet, below the southern ice cap. (The Mars Express is a project of the European Space Agency.)

Although ice and gaseous water have been found on Mars, its surface clearly shows that at some point in the past the planet had plenty of liquid water that had somehow gone missing, according to National Geographic.

If the Martian seas somehow ended up as underground reservoirs, they could provide resources for future human missions to the planet.

Even more intriguingly, astrobiologists say the lake could be conducive to life: Elena Pettinelli of Italy’s Roma Tre University—one of the paper’s authors—points out that the similar environment of the Antarctic hosts living bacteria.

If you believe the news, a human mission to Mars is no longer a sci-fi fantasy. But what problems would we need to overcome? And should we even try?

The InSight lander made a flawless descent to the red planet’s surface in November.

Its mission is to study Mars’s seismic activity, which will allow scientists to gain a better understanding of the thickness of its crust and the size and temperature of its molten core, according to the New York Times.

The InSight joins two NASA Mars rovers on the planet: Curiosity, which is searching for signs of microbial life, and Opportunity, which went silent this past summer during a dust storm that probably disabled its solar panels (the agency is hoping that wind will blow the dust off and allow Opportunity to restart).

Keen to know more about space probes? These little spacecraft are revolutionising our understanding of the Solar System.

The US-based Intergovernmental Panel on Climate Change’s massive report, laid out the bad news: We have only a dozen years to take serious action if we want to keep global warming to 1.5 degrees Celsius.

But the report contained a nugget of hope: Limiting warming to 1.5 C – as opposed to allowing it to reach the 2 degree-limit set by the Paris climate agreement – would be dramatically less disruptive, according to the World Resources Institute; it would help reduce the risk of catastrophic heat events, rising ocean levels, and species loss.

To limit the damage, governments around the globe will need to work together to cut carbon emissions by increasing the world’s energy efficiency, replacing fossil fuels with renewable energy, and protecting—and planting—atmosphere-cleansing forests.

A U.S. climate report released the day after Thanksgiving predicts that climate change could shrink the country’s economy by 10 percent before 2100, providing legislators with motivation to get moving.

Sceptics of man-made climate change dismissed coral bleaching bleaching as either exaggerated or part of a natural cycle – or both. Is the Great Barrier Reef really dying?

A Dutch organization called The Ocean Cleanup launched a large trap to collect trash from the swirling mess of plastic in the middle of the Pacific Ocean where currents meet.

Although the system is still in it’s testing phase, the goal is to float the U-shaped boom through the garbage, and then collect the large plastic pieces for disposal on land before they’re broken down by the sunlight and waves into microplastics -harmful to sea life, according to National Geographic.

Follow these six simple tips to start reducing your reliance on single-use plastic today.

According to the WWF Living Planet Report for 2018, the average number of vertebrate populations—mammals, birds, fish, reptiles, and amphibians—decreased by 60 percent between 1970 and 2014.

Habitat degradation and loss, overfishing, and overhunting top the list of causes.

In South and Central America, animal populations have fallen by a staggering 89 percent, on average.

One way to observe great animals, where possible, is on safari. Vijaya Pratap got closer to a big cat than she’d hoped for.

Some species are bucking the trend, though. Mountain gorillas, a subspecies of the Eastern gorilla, have been shifted from critically endangered status to endangered, reports the International Union for Conservation of Nature and Natural Resources (IUCN)—that’s a step in the right direction.

There are now more than 1,000 mountain gorillas living in the Democratic Republic of the Congo, Rwanda, and Uganda; that’s up from about 680 in the IUCN’s last tally a decade ago.

The primary factor driving their recovery is ecotourism, which funds high numbers of field staffers and on-site veterinary care for the animals, according to the New York Times, as well as leading local and national governments to step up efforts to protect the magnificent animals from poachers and other threats.

Ecotourism has taken hold in Australia and overseas.Read David Levell’s ecotourism piece on swimming with whale sharks.

Despite how you might feel about individual insects, losing them as a whole would be catastrophic for the planet.

A 2018 study published in the Proceedings of the National Academy of Sciences found that the biomass of arthropods (including insects, spiders, and centipedes) in the Luquillo rainforest in Puerto Rico has decreased as much as 60-fold since the 1970s.

Populations of birds, frogs, and lizards that eat arthropods in the forest have also fallen.

The data matches studies published in recent years that show dramatic declines in the numbers of insects around the world, according to the Washington Post.

Love picnics and bugs? To keep insects from biting, stinging or annoying you – and just as importantly, to keep them away from your food – follow these 13 surefire, all-natural tips.

Ever since Pluto got downgraded to dwarf planet status in 2006, our solar system hasn’t felt complete.

But astronomers have had their eye on some unusual goings-on way out beyond Pluto.

This year, they identified an object called 2015 TG387 moving in an unusual elliptical 40,000-year orbit around the sun.

Because it’s so far away from Jupiter, Saturn, Uranus, or Neptune, it’s most likely indicating the presence of a larger, unseen mass, according to the Atlantic.

Not all astronomers agree that Planet Nine (or Planet X) is the only explanation, but they’re continuing to search.

DNA testing of a 90,000-year-old bone fragment pulled out of a Siberian cave showed that it belonged to a teenage girl whose mother was a Neanderthal and whose father was a Denisovan, a genetically distinct group of ancient human relatives that went extinct about 40,000 years ago.

Although researchers had suspected that the species interbred, the discovery of first-generation evidence surprised them, according to National Geographic.

About two percent of DNA from most Europeans and Asians has been passed down from Neanderthals, and Denisovan DNA is found in people from Melanesia, the Pacific islands that include New Guinea.