This story was originally published in our May/June 2023 issue as "Blue Marble, Red Planet." Click here to subscribe to read more stories like this one.For the first time in the history of our solar system, humans are collecting rocks from another planet. Since the Perseverance rover landed on Mars in early 2021, NASA scientists have been guiding it across the Jezero Crater, an ancient martian lakebed. When the rover reaches a site of geological interest, it drills out a small rock sample and ...read more

Christian Tryon, a professor of anthropology at the University of Connecticut, knew stone tools, but he didn’t know teeth.He was looking at a photograph of just that, ancient dentition recovered from a decades-old archaeological site in Lebanon. The photograph had come from the papers of a close associate of Rev. J. Franklin Ewing, the original expedition leader.The Trail to EgbertAt first, Tryon thought the teeth belonged to the remains of an ancient child named “Egbert” by Ewing, bones l ...read more

Around 6 to 8 million years ago, deep in the rainforests of Africa, humans shared a distant ancestor with chimpanzees and bonobos. Since then, a lot has happened. We climbed down from the trees, stood upright, learned to hunt, found fire and spread across the globe. But how? How does human evolution actually work?Toward the end of the Miocene — a geological epoch that occurred from 23 to 5.3 million years ago — humans began to diverge as their own distinctive primate from a common ancestor ...read more

Earlier this year, the world was transfixed by the appearance of balloon-like objects looming over continental United States and other parts of the world. These unidentified flying objects caused such a fear and furor that many were tracked avidly, some disappeared magically and at least one was shot down by the US military.These objects are poorly understood so an important role for researchers is to bring the steely eye of science to bear on the issue of what these things really are.Now we hav ...read more

Marking an engagement or the big wedding day itself with a ring is part and parcel of many cultures today. But you may be surprised to learn that wearing the ring on the fourth finger of the left hand is a tradition dating back at least a thousand years.It’s a practice that’s thought to stem from the belief that a vein ran from this finger all the way to the heart — the vena amoris. This idea is often attributed to the ancient Egyptians, Greeks, and Romans, but the origins of the ring itse ...read more

Science is constantly improving and teaching us marvelous things about ourselves and the world around us. Our understanding of the sciences bends and molds with the times and is impacted by the humans who study it. And humans are, well, human — which means while we can make incredible discoveries, we're also prone to making mistakes. We carry with us biases that can lead to bad science. Here are five cases where scientists got it completely wrong.1.  Humoral Theory(Credit: Book illustration i ...read more

The heart is perhaps the body’s most resilient organ and, along with the brain, its most essential. The female heart, which weighs about eight ounces, beats 100,000 times a day (2.5 billion times in a lifetime), pumping blood with roughly the force needed to squeeze a tennis ball. That’s enough blood in an 80-year lifetime to fill 100 Olympic-sized swimming pools.To sustain this breakneck pace, the heart feeds greedily on its own blood supply, consuming about 5 percent of the body’s oxygen ...read more

This story appeared in the September/October 2020 issue as part of Discover magazine’s 40th anniversary coverage. We hope you’ll subscribe to Discover and help support our next 40 years of delivering science that matters. The story was updated further in 2023. As dawn broke on April 15, 1912, the ‘Unsinkable Ship’ sank into the Atlantic. Only two days earlier, Titanic set out on its voyage carrying more than 2200 crew members and passengers. The world-class facilities aboard the vess ...read more

Typical spacecrafts orbiting the Earth aren’t extremely far away. They’re only a few hundred miles above our heads. So, when it’s time to return to solid ground, it’s a relatively short trip.However, spacecrafts and similar objects in orbit are also moving at exceptionally high speeds. We’re talking 17,000 mph for a low-Earth orbit satellite or spacecraft, and even faster for higher orbits.Combined, these two factors create a dilemma — and a whole lot of heat — when bringing spacec ...read more

Drug overdose deaths have skyrocketed in the U.S. in recent years. In 2021, 106,699 people died of overdoses. According to the Centers for Disease Control and Prevention, that number was up 14 percent from the year before. Experts contend that it’s not that more people are using drugs; it’s that the drug supply has been contaminated with highly potent fentanyl, a synthetic opioid that is 50 times stronger than heroin. Overdose deaths that included fentanyl increased by 22 percent last year ...read more