SpaceX's Starship rocket took off again Tuesday for its sixth test flight. Crowds, including President-elect Donald Trump, gathered at the launch site in Texas to watch it fly part way around the world to the Indian Ocean. Starship – the largest rocket ever built – is the dream of Elon Musk, who hopes to make humans a multiplanetary species. But building the rocket is having a real impact on Earth. The launch site is located in the middle of one of Texas' largest wildlife sanctuaries and environmentalists say every launch is causing damage. Plus, how government regulation of launches may change in a second Trump administration. Want to hear more on the future of space exploration? Email us your ideas to shortwave@npr.org — we'd love to hear from you! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

For decades, Coho salmon were turning up dead in urban streams the Pacific Northwest. The salmon would stop swimming straight, and then die before they had a chance to spawn. Researchers worried that unless they figured out the cause, the species would eventually go extinct. Enter a formidable crew of biologists, modelers, community scientists, environmental chemists. After eventually ruling out the obvious suspects — things like temperature, oxygen levels and known toxins — researchers eventually zeroed in on a prime suspect: chemicals in tires. But the question remained: Which one? If you liked this episode, check out our other episodes on satellites monitoring emissions and how air pollution could create superbugs.Want to hear more environmental stories or science mysteries? Tell us by emailing shortwave@npr.org!Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Many people are gearing up for holiday conversations with loved ones who may disagree with them — on everything from politics to religion and lifestyle choices. As the conversations unfold, these divisions are visible in our brains too. These conversations can get personal and come to a halt fast. But today on the show we get into research in neuroscience and psychology showing that as much as we disagree, there are ways to bridge these divides – and people who are actively using these strategies in their daily lives. Want to hear more neuroscience and psychology? Email us your ideas to shortwave@npr.org — we'd love to hear from you!Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Getting enough sleep regularly can be tough — and even harder when you're traveling for the holidays. "We need sleep like we need water," says Jade Wu, a behavioral sleep medicine psychologist and author of the book Hello Sleep. She and host Regina G. Barber discuss what's happening to our bodies when we get jet lag and the clocks in our body get out of whack. They also get into the science of the circadian rhythm and how to prepare for a long flight across time zones. Check out CDC's website for tips on minimizing jet lag.Want to hear more science of holiday living? Email us your ideas to shortwave@npr.org — we'd love to hear from you! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

This critter lurks in the ocean's midnight zone, has a voluminous hood, is completely see through and is bioluminescent. It's unlike any nudibranchs deep sea experts have ever seen before — and now, the researchers who spent twenty years studying them have finally published their findings. Have another scientific discovery you want us to cover on a future episode? Email us at shortwave@npr.org — we might feature your idea on a future episode! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

As global warming continues and space technology improves, there is more and more talk about the growing possibility of a sci-fi future in which humans become a multiplanetary species. Specifically, that we could live on Mars. Biologist Kelly Weinersmith and cartoonist Zach Weinersmith have spent the last four years researching what this would look like if we did this anytime soon. In their new book A City On Mars, they get into all sorts of questions: How would we have babies in space? How would we have enough food? They join host Regina G. Barber and explain why it might be best to stay on Earth. Kelly and Zach Weinersmith's book A City On Mars is out now.Have another space story you want us to cover on a future episode? Email us at shortwave@npr.org — we'd love to hear from you! Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

One in four U.S. households experiences a power outage each year. Scientists at Oak Ridge National Laboratory are working on technology they hope will help fix electric grids: drones. They're betting that 2-ft. large drones connected to "smart" electric grids are a cost-effective step to a more electrified future.Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave. Have an idea for a future episode? We'd love to know — email us at shortwave@npr.org!Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

In this episode, you're invited to the fermentation party! Join us as we learn about the funk-filled process behind making sauerkraut, sourdough and sour beer. Plus, no fermentation episode is complete without a lil history of our boy, yeast.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

A pivotal week in Corey Gray's life began with a powwow in Alberta and culminated with a piece of history: The first-ever detection of gravitational waves from the collision of two neutron stars. Corey was on the graveyard shift at LIGO, the Laser Interferometer Gravitational-Wave Observatory in Hanford, Washington, when the historic signal came. This episode, Corey talks about the discovery, the "Gravitational Wave Grass Dance Special" that preceded it and how he got his Blackfoot name. (encore)Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

In North-Central New Jersey, there is a backyard teeming with around 200 turtles. Many of these shelled creatures have been rescued from the smuggling trade and are now being nursed back to health in order to hopefully be returned to the wild. Science reporter Ari Daniel joins host Regina G. Barber to tell the story behind one man's efforts to care for these turtles and to ensure they have a chance at another (better) life. Read more of Ari's reporting.Have an idea for a future episode? We'd love to know — email us at shortwave@npr.org! Listen to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy