In less than 10 days, the world will witness the winter solstice, or the shortest day of the year. Half of the Earth will be tilted the farthest away from the sun, and we will plunge into the dark. So today we thought we’d play another story about the dark. One of the darkest places in the universe actually: a black hole. But not just any black hole, a really tiny black hole, the size of an atom.

We start the story on a calm morning in Siberia. All of a sudden, a large ball of fire appears in the sky. A forest was flattened, roofs were blown off houses, windows were shattered, fish were thrown from streams. This was the “Tunguska event.” But what happened? What hit Earth? It’s still up for debate. Radiolab producer Annie McEwen explores the possibility that it might have been a tiny black hole. Then Senior Correspondent Molly Webster asks what happens to the stuff that falls into a black hole, and tells us about how finding an answer culminated into her writing a children’s book called “Little Black Hole!”

Special thanks to Matt Caplan, a physicist at Illinois State University who worked on a team whose recent paper taught us what the impact crater left behind by a primordial black hole would actually look like. We also want to thank Priyamvada Natarajan and Brian Greene.

Articles:

Read more about the Tunguska impact event!

Check out the paper which considers the shape of the crater a primordial black hole would make, should it hit earth: “Crater Morphology of Primordial Black Hole Impacts”

Curious to learn more about black holes possibly being dark matter? You can in the paper, “Exploring the high-redshift PBH- ΛCDM Universe: early black hole seeding, the first stars and cosmic radiation backgrounds”

Books:

Get your glow on – check out Senior Correspondent Molly Webster’s new kids book, a fictional tale about a lonely “Little Black Hole.”

Radiolab was created by Jad Abumrad and is edited by Soren Wheeler. Lulu Miller and Latif Nasser are our co-hosts. Dylan Keefe is our director of sound design. Our staff includes: Simon Adler, Jeremy Bloom, Becca Bressler, W. Harry Fortuna, David Gebel, Maria Paz Gutiérrez, Sindhu Gnanasambandan, Matt Kielty, Annie McEwen, Alex Neason, Valentina Powers, Sarah Qari, Sarah Sandbach, Arianne Wack, Pat Walters and Molly Webster. Our fact-checkers are Diane Kelly, Emily Krieger and Natalie Middleton. Production help from Tanya Chawla. Sound mixing by Joe Plourde.

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The Littlest Black Hole

Terrestrials