A journey with two asteroids

Samantha & Bradley

We are Samantha and Bradley — and we are taking you into space.

A lovingly created journey from Earth to the asteroid belt
This is really true

We are two asteroids!

Hello, space explorers! We are Samantha and Bradley — two real asteroids. We orbit the Sun between Mars and Jupiter. Would you like to get to know us?

10 kmSamantha’s estimated diameter
5.8 kmBradley’s estimated diameter
4.24 yearsSamantha’s orbital period
3.30 yearsBradley’s orbital period
Two names in the universe

This is how we look in space

Out here, beyond Mars, we follow our orbits around the Sun.

(3147) Samantha
(2383) Bradley
How Samantha got her name

A girl whose letter made history

I, Samantha, was discovered on December 16, 1976, by astronomer Lyudmila Ivanovna Chernykh at the Crimean Astrophysical Observatory.

My name honors Samantha Smith. During the Cold War, this American girl wrote to the Soviet leadership and spoke up for peace and friendship.

We think it is wonderful that a child could make such a difference with one letter. And now I carry her name through our solar system.

You may wonder what Samantha Smith wrote. It was 1982, and many people feared a nuclear war between the United States and the Soviet Union. Samantha was only ten, and she decided to ask directly.

Here is a child-friendly retelling of her brave letter in English:

November 1982 · United States
Dear Mr. Andropov,

My name is Samantha Smith, and I am ten years old. I learned that you are now leading the Soviet Union.

I worry that our countries could start a nuclear war one day. Do you want to prevent that? And what will you do to make sure it does not happen?

I also do not understand why our countries are so afraid of one another. Why can we not live together peacefully instead of fighting over power and borders?

I wish for people everywhere to live happily and in peace.

Sincerely,
Samantha Smith
1982

Historically inspired paraphrase in English — not a facsimile or verbatim reproduction of the original letter. Learn about the original letter.

And here is the amazing part: Yuri Andropov really replied. In April 1983 he even invited Samantha to visit the Soviet Union. That summer, she traveled there with her parents and met children her own age.

We believe you do not have to be an adult to ask an important question. Sometimes something big begins with a single letter.

How Bradley got his name

Our story leads to Arizona

I, Bradley, was discovered on April 5, 1981, by Edward L. G. Bowell at Lowell Observatory’s Anderson Mesa Station near Flagstaff, Arizona.

I was named after my discoverer’s friends, Martin and Maud Bradley. It is a wonderful coincidence that a boy on Earth is named Bradley too.

At around 5.8 kilometers across I am wider than some towns. Imagine walking all the way from one side of me to the other — quite a hike!

I travel around the Sun between Mars and Jupiter. One complete orbit takes me around 3 years and 4 months. Every journey is a little different as the planets keep moving too.

And here is another fun fact: I spin once on my axis in about 5.8 hours On Earth a rotation takes almost 24 hours. Here, day and night would alternate much faster — though I have no breathable air or blue sky.

An astronomer discovered me while watching the night sky and noticing a tiny point of light moving against the stars. That barely visible point became a catalogued celestial body with its own number and name: (2383) Bradley.

Our address in the solar system

Where can you find us?

SunEarthMarsBradleySamanthaJupiter

You can find us in the asteroid belt between Mars and Jupiter. Our map is simplified and not to scale.

Samantha in detail

Asteroid (3147) Samantha

Discovered: 16.12.1976
Provisional designation: 1976 YU₃
Average distance from Sun: about 2.625 AU
Orbital period: about 1,550 days
Rotation: about 5.27 hours
Diameter: about 10 km
Orbital inclination: about 3.55°
Albedo: about 0.07

Bradley in detail

Asteroid (2383) Bradley

Discovered: 05.04.1981
Provisional designation: 1981 GN
Average distance from Sun: about 2.218 AU
Orbital period: about 3.30 years
Rotation: about 5.8 hours
Diameter: about 5.823 km
Orbital inclination: about 3.57°
Albedo: about 0.227

Let’s take a closer look

Real pictures from space

No spacecraft has taken known detailed close-up pictures of either of us. So nobody knows exactly what our surfaces look like. The images on this page are artistic interpretations, not real close-up photographs.

If you want to see what other asteroids look like, you can explore real images of Vesta and Bennu.

NASA: Asteroid information and images
NASA: Asteroid Vesta
NASA: Asteroid Bennu

Ask us about space

Seven questions for us

Are we stars?

No. We do not produce our own light like stars. We reflect sunlight.

Can you see us from Earth?

No, we are too small and too far away for the naked eye. To observe us, you need powerful telescopes and accurate orbital data.

Why don’t we fall into the Sun?

Because we also move sideways very quickly. That keeps us in orbit.

How much would you weigh on us?

Very little! Our gravity is tiny. But visiting without a spacesuit and safety equipment would still be dangerous.

How long would the journey to us take?

A spacecraft from Earth could take many months or even years to reach us. The travel time depends on its trajectory and propulsion.

How old are we?

We contain material from the early solar system — around 4.6 billion years ago.

Could you live on us?

In reality, you could not simply live on us: we have no breathable air or comfortable living conditions. But who knows? Perhaps scratching our surfaces a little might reveal a surprise…

“We are far away — yet you can still keep us close to your hearts.”

Our journey through space continues.