What Are the Earliest Known Vertebrates on Land?

As COVID Cases Rises, Effectiveness Of Vaccines Lessens In Kids

As parts of the country continue to see waves of infection from the omicron variant of COVID-19, parents of children over age five have taken heart at the availability of vaccines—while parents of kids five and under have continued to wait for an approved dose. But even as the case numbers continue to climb, the vaccines are less effective against the more-virulent omicron variants—and, for some reason, dramatically less effective in kids.

Koerth joins Ira to discuss the story, and why experts say it’s still worthwhile getting vaccinated even if the vaccines don’t have the dramatic performance seen at the beginning of the vaccination phase of the pandemic. They also talk about a bird flu outbreak troubling poultry farms around the world, the odd immune system of the sleepy lizard, and how scientists are trying to catch a whiff of the odors of ancient Egypt.

 

Meet The ‘Gentle Giant,’ Your Friendly Neighborhood Black Hole

It wasn’t long ago that the idea of capturing an image of a black hole sounded like a joke, or an oxymoron. How do you take a picture of something so dense that it absorbs the very light around it?

But three years ago, we got our first good look with help from the Event Horizon Telescope, which is actually multiple radio telescopes all linked together. That picture was a slightly blurry, red-and-orange doughnut—the best picture to date of the supermassive black hole at the center of a galaxy called Messier 87, which is called Messier 87* or M87*. (Black holes are given an asterisk after the name of their location). Today, it’s possible to buy jewelry and t-shirts with that picture, drink out of a M87*-adorned coffee cup, or just make it your phone background. Now that the first picture of a black hole is practically a pop culture meme, how do you one-up that? In the past weeks, the Event Horizon Telescope team alluded to a new ‘breakthrough’ hiding in the Milky Way.

On Thursday, the team unveiled that breakthrough: the first image of our nearest black hole neighbor in the heart of our galaxy. Sagittarius A* is a “gentle giant,” says Feryal Ozel, a member of the global collaboration that created this image. It consumes far less of the gas swirling nearby than M87*, and is far fainter as a result. The Milky Way’s black hole also lacks the galaxy-spanning jets of M87* and, due to its smaller size, the gas around it moves so fast that it took years longer to capture a clear picture.

Ira talks with Ozel about what it takes to obtain such a picture, and what it can tell us about the extreme, high-temperature physics of black holes throughout the universe.

 

What Was It Like To Witness The End Of The Dinosaurs?

66 million years ago, a massive asteroid hit what we know today as the Yucatán Peninsula of Mexico. Many people have a general idea of what happened next: The age of the dinosaurs was brought to a close, making room for mammals like us to thrive.

But fewer people know what happened in the days, weeks, and years after impact. Increased research on fossils and geological remains from this time period have helped scientists paint a picture of this era. For large, non-avian dinosaurs like Triceratops and Tyrannosaurus rex, extinction was swift following the asteroid impact. But for creatures that were able to stay underwater and underground, their post-impact stories are more complicated.

Joining Ira to discuss her book The Last Days of the Dinosaurs is Riley Black, science writer based in Salt Lake City, Utah.

 

Transcripts for each segment will be available the week after the show airs on sciencefriday.com.

Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.