In early February 2020, China locked down more than 50 million people, hoping to hinder the spread of a new coronavirus. No one knew at the time exactly how it was spreading, but Lidia Morawska, an expert on air quality at Queensland University of Technology in Australia, did not like the clues she managed to find.

It looked to her as if the coronavirus was spreading through the air, ferried by wafting droplets exhaled by the infected. If that were true, then standard measures such as disinfecting surfaces and staying a few feet away from people with symptoms would not be enough to avoid infection.

Continue reading “Could the Bird Flu Become Airborne?” →

Our solar system contains planets, dwarf planets, asteroids and comets — but only one world is known to harbor life. Scientists have long debated whether Earth is truly unique. Perhaps our planet just happened to have the right combination of ingredients, conditions and timing to allow life to emerge.

But a pinch of grit from a distant asteroid collected by a NASA spacecraft holds hints that our planet may not be so special. A team of researchers reported in the journal Nature on Wednesday that the asteroid, known as Bennu, contains a wealth of organic molecules, including many crucial building blocks of life. The chemistry that produced them might be going on today on the ice moons of Jupiter and Saturn.

Continue reading “Lurking Inside an Asteroid: Life’s Ingredients” →

Chimpanzees live only in African rainforests and woodlands. Orangutans live only in the jungles of Indonesia. But humans live pretty much everywhere. Our species has spread across frozen tundras, settled on mountaintops and called other extreme environments home.

Scientists have historically seen this adaptability as one of the hallmarks of modern humans and a sign of how much our brains had evolved. But a new study hints that maybe we aren’t so special.

Continue reading “Extinct Human Species Lived in a Brutal Desert, Study Finds” →

In our digital age, few things are more irritating than a slow internet connection. Your web browser starts to lag. On video calls, the faces of your friends turn to frozen masks. When the flow of information dries up, it can feel as if we are cut off from the world.

Engineers measure this flow in bits per second. Streaming a high-definition video takes about 5 million bps. The download rate in a typical American home is about 262 million bps.

Continue reading “The Speed of Human Thought Lags Far Behind Your Internet Connection, Study Finds” →

Some 45,000 years ago, a tiny group of people — fewer than 1,000, all told — wandered the icy northern fringes of Europe. Across thousands of miles of tundra, they hunted woolly rhinoceros and other big game. Their skin was most likely dark. To keep warm in the bone-chilling temperatures, they probably wore the hides and furs of the animals they killed.

Continue reading “Oldest Human Genomes Reveal How a Small Group Burst Out of Africa” →