Why Voyager 1 Hasn’t Hit Anything in 49 Years（原声文稿）

Transcript of 飞了49年一物未撞，旅行者1号是怎么活下来的？ （中文完整文稿）。

Voyager 1 has been flying for 49 years at 38 ,000 miles an hour, straight through the asteroid belt, past Jupiter, past Saturn, and out past the Sun's own outer boundary.

And in all that time, nothing has ever hit it hard enough to matter.

Not a rock, not a pebble. That is not the strange part.

The strange part is what Voyager heard when the tiny things did hit it, and the moment, far out in the dark, when the hits stopped showing up.

Nobody had a clear explanation for that silence.

And on November 18th, 2026, Voyager 1 crosses a line no human -made object has ever crossed, carrying something built to outlast the planet that made it.

Hollywood loves the asteroid belt, a blizzard of tumbling rock, boulders spinning past, a ship weaving through at the last second.

Voyager 1 crossed the real one on its way to Jupiter without dodging a thing.

There are millions of objects out there, but on average they sit about 600 ,000 miles apart.

That is more than twice the distance from Earth to the Moon, between one rock and the next.

Stand on almost any asteroid, and you would probably not see a single other one in your sky.

Shrink the whole scene down until Voyager is the size of a mosquito.

At that scale, the typical gap between two asteroids would be around 800 miles.

That's farther than New York to Chicago, with one rock at each end and a mosquito somewhere in the middle.

Now ask yourself how often that mosquito would bump into anything.

That's the asteroid belt, the scary part of the solar system, and it's mostly a desert. So that's the answer, right?

Space is empty and Voyager got lucky. Except it didn't just get lucky.

Voyager has been hit, again and again, and we know exactly what it sounded like.

Since 1990, Voyager 1 has been blind.

On Valentine's Day that year, 3 .7 billion miles out, the team swung its cameras back toward us one final time and caught Earth as a spec smaller than a single pixel. Then they switched the cameras off for good.

If a rock ever came at it, Voyager would never see it coming. But it can feel things.

Two thin antennas, each about 33 feet long, stick out from its body.

They belong to the plasma wave instrument, built to listen to electric ripples in the thin gas of space. It was never meant to detect dust.

Then, at Saturn, the team behind that instrument, led by physicist Don Gernett at the University of Iowa, noticed something odd in the data. Sharp, sudden cracks.

Each one was a grain of dust, far thinner than a human hair, slamming into the spacecraft so fast that it vaporized into a tiny puff of charged gas.

That puff washed over the antennas and the instrument heard it as a click.

At Neptune, Voyager 2 took up to 280 of those hits every second.

A hailstorm you could only hear.

And Voyager 1 kept hearing them long after the planets were behind it.

In 1997, Gernet's team went back through the recordings from deep space, checking every single spike by eye.

Out to about 50 times the distance from Earth to the Sun, they found a small but steady trickle. 27 hits in about 11 hours of recordings.

Then, somewhere past that point, the clicks stopped.

The recordings were just as good. At the same rate, they should have caught around 27 more.

They caught zero. Voyager 2 went quiet too, even earlier. The team admitted they had no specific explanation.

Their best guess was dust shed by comets, scattered unevenly through the dark.

Whatever the cause, it means even dust out there is patchy.

Voyager wasn't flying through an even haze.

It was crossing long stretches where nothing its instruments could detect touched it at all.

What On August 25, 2012, about 11 billion miles from home, Voyager 1 crossed the heliopause, the edge of the bubble the sun's wind blows around all the planets.

Its twin crossed six years later and took the temperature of the gas on the other side, somewhere between 54 ,000 and 90 ,000 degrees Fahrenheit, hotter than anyone had predicted, and Voyager flew straight through it without a scratch.

Because temperature only measures how quickly each particle is zipping around.

What actually burns you is the number that strike your skin and out there there are almost none.

In 2013 an eruption on the Sun set that gas ringing like a bell and the pitch of the ringing gave away how thick it was. About one electron per cubic inch.

The air in your lungs right now packs roughly 400 billion billion molecules into that same space.

Close your fist around a cubic inch of interstellar space and you might be holding a single electron.

On November 18th, 2026, Voyager 1 reaches 16 .1 billion miles from Earth.

That is so far that even a beam of light racing at 186 ,000 miles every second takes an entire day to get there.

No human -made object has ever been one light day away.

Voyager's project manager, Susie Dodd, explained it this way.

If she says good morning to Voyager 1 on a Monday, the answer arrives on Wednesday morning.

If something breaks out there, the team won't even know until the next day, and their fix lands a day after that. Every rescue now takes at least two days.

And yet, at the speed it is moving, about a million miles every day, it would need nearly 18 ,000 more years to cover a single light year.

Half a century of flying bought it a single light day.

A light year is longer than all of recorded history three times over.

Three centuries from now, it arrives at the Oort Cloud, a giant sphere of frozen objects wrapped around the whole solar system. Possibly billions, maybe trillions of them.

Getting through it takes something like 30 ,000 years, and the icy bodies out there are scattered so thinly that the odds say Voyager won't brush a single one.

In about 44 ,000 years, Voyager 1 makes its next pass by another star, a dim red dwarf called Gleese 445.

And Voyager isn't even doing most of the work.

That star is racing toward it faster than Voyager is moving toward the star. Its closest approach?

About two light years.

Even its closest brush with another star leaves a gap so wide that light needs two full years to cross it. But Voyager won't be awake for any of that.

Its electricity comes from the heat of plutonium slowly falling apart, and every year it loses about four watts.

To keep it warm enough to survive, engineers have been turning its systems off one by one.

In April, 2026, they shut down another instrument, leaving just two of its original 10 still running. One measures magnetic fields.

The other is the ear, the plasma wave instrument that once heard the dust.

This summer, they pulled off a risky power shuffle on its twin that the teen calls the Big Bang and lined up the same move for Voyager 1, but the plutonium doesn't care how clever they are.

Sometime in the 2030s, the transmitter goes quiet.

The huge antennas back on Earth will still point at that patch of sky, waiting for a signal that never comes.

And none of that slows it down.

No air, no friction, it keeps coasting whether anyone is listening or not.

So here is the real reason it has never hit anything big.

The rocks sit farther apart than our minds can picture, and beyond the planets, even the dust turned out to be thin and patchy, sometimes too thin to register at all.

Bolted to Voyager's side is the golden record.

90 minutes of music, greetings in 55 languages and the sounds of Earth.

Copper, plated in gold, sealed in aluminum, built to last about a billion years.

A billion years is roughly how long scientists think Earth has before a brightening sun boils its oceans away.

And astronomers who modeled Voyagers' path through the galaxy found it could drift for trillions of years without ever coming close to a star. So follow the timeline forward.

In about a billion years, Earth's oceans are gone.

A few billion years after that, the Sun swells into a red giant, and a 12 -inch disc of gold -plated copper is still out there, falling between the stars, still carrying the music and the voices of a planet that no longer exists.

It may become the last thing anywhere that proves we were ever here, and right now, Tonight it's still drifting deeper into the dark at 38 ,000 miles an hour