Our favorite science news stories of 2019

A lost continent. Bullets made of dark matter. A “cow” in space. These were the subjects of some of our favorite stories about scientific findings this year. The items below don’t necessarily reflect the most important science of 2019. (For that, see our Breakthrough of the Year.) They’re just some of the articles we enjoyed reading the most. We hope you’ll agree!

Early humans domesticated themselves, new genetic evidence suggests

Humans get a lot of credit for domesticating cats, dogs, and other animals. But the most important creature we may have tamed is ourselves. New genetic evidence suggests that our temperaments—and even our faces—could be the result of kicking bullies out of our early societies, making us a friendlier and more cooperative bunch.

‘Wood wide web’—the underground network of microbes that connects trees—mapped for first time

Think of it as the internet for trees. For the first time, scientists have mapped how millions of species of fungi and bacteria swap nutrients between soil and the roots of trees, forming a vast, interconnected web of organisms throughout the woods. The findings could help researchers better predict the role forests will play in climate change.

Astronomers still can’t decipher the ‘Cow,’ a mysterious explosion in deep space

Everyone loves a good astronomical mystery, and this one’s stranger than most: an unusually bright object that appeared in the sky in 2018, which scientists are calling AT2018cow, or the “Cow.” Is it a flaring white dwarf? A star being ripped apart by a black hole? Astronomers still aren’t sure. Whatever it is, says one, “It’s super weird.”

Lab rats play hide-and-seek for the fun of it, new study shows

There’s a lot more going on in the rodent brain than we appreciate. Rats exercise just for the fun of it. They laugh when tickled. And, according to a new study, they enjoy a good game of hide and seek. They even play with people.

See the new Star Wars–like display that could ‘revolutionize’ virtual reality

A galaxy “far, far away” may not be so distant after all. Researchers have invented a Star Wars–like 3D display that simultaneously projects video, sound, and even the sensation of touch. They haven’t quite created Princess Leia’s famous distress call. But such an advance is no longer light-years away.

This microbe no longer needs to eat food to grow, thanks to a bit of genetic engineering

Imagine never having to sit—or pay—for a meal again. Scientists have made this a reality for one lucky Escherichia coli bacterium. Thanks to a bit of genetic engineering, the once sugar-scarfing microbe can now survive simply by absorbing carbon dioxide, like plants do. Future work could create microbes that suck greenhouse gas out of the air and turn it into medicines and other important compounds.

Human speech may have a universal transmission rate: 39 bits per second

Travel the world, and some languages will sound much faster than others. But according to a new study, they all seem to convey the same amount of information in the same amount of time. The rate is about 39 bits per second, or approximately twice the speed of Morse code.

Geologists uncover history of lost continent buried beneath Europe

Forget Atlantis. Greater Adria is the real deal. Geologists have reconstructed the nearly quarter-of-a-billion-year-long history of this giant landmass, which now lies submerged—not beneath an ocean somewhere, but largely below southern Europe.

If this type of dark matter existed, people would be dying of unexplained ‘gunshot’ wounds

Dark matter hunters have added an unusual new detector to their list: human flesh. If a certain type of the elusive substance existed, it would occasionally kill people, vaporizing a tubular wound through them. But because no one has died from such injuries, this type of dark matter is not real, scientists conclude. Still, it’s not a bad idea for a horror movie.

Here’s a better way to convert dog years to human years, scientists say

Common wisdom says that to figure out how old your dog is in human years, simply multiple his age by seven. Now, researchers say they’ve come up with a better—and far more scientific—way, one that involves an “epigenetic clock.” Try the calculator yourself; many readers have, making it our most popular story of the year.