In 1908, on a sunny, clear, quiet morning in Siberia, witnesses recall seeing a blinding light streak across the sky, and then… the earth shook, a forest was flattened, fish were thrown from streams, and roofs were blown off houses. The “Tunguska event,” as it came to be known, was one of the largest extraterrestrial impact events in Earth’s history. But what kind of impact—what exactly struck the earth in the middle of Siberia?—is still up for debate. Producer Annie McEwen dives into one idea that suggests a culprit so mysterious, so powerful, so… tiny, you won’t believe your ears. And stranger still, it may be in you right now. Or, according to Senior Correspondent Molly Webster, it could be You.

EPISODE CREDITS

Reported by - Annie McEwen and Molly Webster
Produced by - Annie McEwen and Becca Bressler
with help from - Matt Kielty
Original music and sound design contributed by - Jeremy Bloom, Annie McEwen, Matt Kielty
Mixing by - Jeremy Bloom
with dialogue mixing by - Arianne Wack
Fact-checking by - Diane Kelly
and edited by - Alex Neason

GUESTS
Matt O’Dowd (https://www.mattodowd.space/)

Special Thanks:

Special thanks to, Matthew E. Caplan, Brian Greene, Priyamvada Natarajan, Almog Yalinewich

EPISODE CITATIONS

Videos:

Watch “PBS Space Time,” (https://zpr.io/GNhVAWDday49) the groovy show and side-gig of physicist and episode guest Matt O’Dowd

Articles:

Read more (https://zpr.io/J4cKYG5uTgNf) about the Tunguska impact event!

Check out the paper (https://zpr.io/vZxkKtGQczBL), 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 (https://zpr.io/sPpuSwhGFkDJ), “Exploring the high-redshift PBH- ΛCDM Universe: early black hole seeding, the first stars and cosmic radiation backgrounds”

Books:

Get your glow on – Senior Correspondent Molly Webster has a new kids book, a fictional tale about a lonely Little Black Hole (https://zpr.io/e8EKrM7YF32T)

Our newsletter comes out every Wednesday. It includes short essays, recommendations, and details about other ways to interact with the show. Sign up (https://radiolab.org/newsletter)!

Radiolab is supported by listeners like you. Support Radiolab by becoming a member of The Lab (https://members.radiolab.org/) today.

Follow our show on Instagram, Twitter and Facebook @radiolab, and share your thoughts with us by emailing radiolab@wnyc.org.

Leadership support for Radiolab’s science programming is provided by the Gordon and Betty Moore Foundation, Science Sandbox, a Simons Foundation Initiative, and the John Templeton Foundation. Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation.

This week on the New Yorker Radio Hour, a conversation with the singer and songwriter Regina Spector, along with a live performance.

That's the New Yorker Radio Hour, wherever you listen to podcasts.

And today we have 2 very different stories from 2 very different reporters, 1 of whom is you, Molly.

Who each got pulled down into the same very strange and very dark place.

And we're going to begin with producer Annie McEwen.

It is June, it is a bright, sunny morning.

And in this remote part of Russia, it's mostly forest, swamp, bugs, reindeer.

The few people in the area are waking up, stretching their legs, making breakfast, and everything's cool.

It is promising to be just a beautiful day.

But that is all about to change because just after 7 a.m., something appears low in the sky, as bright as a second sun.

From oral histories gathered years later, people reported looking up and seeing this thing rocketing towards Earth faster than a bullet.

It quickly grows into a giant ball of fire, dragging behind it this tail of blue and white light.

It arcs across the sky, disappearing over the horizon.

Then, A shockwave pulses through the forest, flattening trees, shattering windows, throwing people to the ground.

Some people reported a hot blast of wind.

Others reported a colossal amount of smoke and fire.

And luckily, because it's such a remote region, despite the fact that 800 square miles of forest were flattened, only somewhere between 0 and 3 people are killed.

And I don't know, have either of you heard of this before?

And today, this is still considered the largest impact event in recorded human history.

So there's a some thing that like hit us?

So A bunch of scientists go plunging into the forest to try to figure out what the heck just happened.

They scramble over fallen log after fallen log, through dense bog after dense bog, for miles and miles until finally they realize...

They have no idea what happened out here.

They can't find any evidence of what caused this huge explosion.

Like, they sort of figured this must have been an asteroid, So they thought they'd find debris from an asteroid, like space rock.

They don't find a single bit of space rock in this whole area.

And not only that, an asteroid that would have caused this much destruction should have left probably something like a three-quarter mile long impact crater.

And they don't find any crater whatsoever.

In 800 square miles of destruction, there was like nothing from space.

Yeah And I think that like that's what the scientists were like Well, we have to we have to find what obviously should be there And so all kinds of ideas cropped up Like some people thought it was maybe like a natural gas bubble that bursts from beneath Earth's crust.

But that doesn't explain like the bright light in the sky.

Some people thought maybe it was like a strange kind of volcanic eruption.

But again, doesn't really explain the light moving through the sky.

1 guy for a while thought that he had found the crater and it was a lake, but then the locals were like, yo, that lake was here.

So they were trying for many, many years to figure out what the heck it was.

But so the main theory and the 1 that holds strongest today is that it was an asteroid, a really big 1.

Estimates put it at 120 feet across, 220 million pounds.

Or like an apartment building headed toward planet Earth.

And the theory is that it came into Earth's atmosphere at kind of a weird angle, and so it stayed in the atmosphere and started to overheat.

And it got so hot that eventually it just went boom.

Wait, but then are there some chunks or it's just dust and fire and energy?

Like, shouldn't there be some pieces of this like somewhere out there?

And that's the part that is still a little weird.

But, you know, it's pretty plausibly an atmospheric explosion.

And I think, You know, most scientists have sort of dusted their hands off and moved on to the next question with regards to Tunguska.

Some still believe it wasn't an asteroid.

Professor at the City University of New York, Lehman College.

And I reached out to Matt because I had recently seen him on his side gig.

Have you ever asked, what is beyond the edge of the universe?

This really awesome physics YouTube show.

Alternate theory of what could have caused the Tunguska event of

Like a black hole, like a space black hole did this?

I don't know, radiated a death wave toward planet Earth?

Matt's talking about a black hole actually hitting Earth.

Which sounds impossible, because usually when we're talking black holes,

We're talking about these big, terrifying, churning places in space where gravity is just so strong that not even light can escape it.

They eat stars and planets and gas and they have all these almost supernatural qualities like they

warp the space around them, change the flow of time and all of that awesome stuff that comes out of general relativity.

But If 1 of these black holes approached Earth, its gravitational pull would be so strong that

Earth would be, they call it, spaghettified.

The entire planet would begin to stretch towards the black hole, And then as it punched in,

Earth would essentially follow it through the hole that it made.

So you can imagine kind of Earth just folding in afterwards and it would probably follow the black hole in this kind of stream of super hot stuff.

Until all of Earth, Everything on it, everything in it, is ripped apart into individual atoms and Earth is devoured.

Okay, so this obviously is not a very plausible explanation for the Tunguska event.

But that's because there's 1 very important difference between these black holes and the 1 that potentially destroyed 800 square miles of Siberian forest.

Which is that rather than being this giant monster, the Tunguska black hole would have been a really, really

We're talking like the size of a hydrogen atom.

That is very small for a black hole, okay.

Now so these tiny little black holes are special black holes Because typically a black hole gets made after a star explodes.

But these tiny little black holes, they got made in this 1 particular explosion.

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Little Black Holes Everywhere