The Mystery of the Moon Trees

The tree looked like any other. 

Its wide leaves were bright green. Its rough bark had moss growing on it. Its thin branches swayed gently in the breeze.

But this tree was special. 

A third-grader noticed the sycamore in 1996. It stood tall and proud on a patch of grass in Cannelton, Indiana. In front of the tree was a wooden sign. The sign simply said “Moon Tree.” 

Wait. What is a Moon Tree? 

The tree looked normal. Its leaves were bright green. Its bark had moss growing on it. Its branches swayed in the breeze.

But this tree was special. 

A third-grader noticed the sycamore in 1996. It was on a patch of grass in Cannelton, Indiana. A wooden sign in front of the tree said “Moon Tree.” 

Wait. What is a Moon Tree?

That’s the question the third-grader asked her teacher, Joan Goble. 

Ms. Goble’s class was doing a project on local trees. The teacher and her students were making a list of possible trees they could study. That’s when the girl said she had seen the sycamore with the mysterious sign. It was at a Girl Scout camp nearby.

“What is a Moon Tree?” the student asked.

Ms. Goble had no idea. But she thought someone at NASA might. NASA is the U.S. government agency that focuses on exploring space. If anyone knew what a tree in Indiana had to do with the moon, it would be someone at NASA.

Ms. Goble emailed a scientist there named Dave Williams. But even Williams had never heard of Moon Trees. 

So he decided to find out. “It seemed really interesting,” Williams remembers

That’s the question the third-grader asked her teacher, Joan Goble. 

Ms. Goble’s class was doing a project on local trees. That’s when the girl
said she had seen the tree with the mysterious sign. It was at a Girl Scout camp nearby. 

“What is a Moon Tree?” the student asked. 

Ms. Goble didn’t know. But she thought someone at NASA might. NASA is the part of the U.S. government that focuses on exploring space. 

Ms. Goble emailed a scientist there named Dave Williams. But even Williams had never heard of Moon Trees.

So he decided to find out. “It seemed really interesting,” Williams remembers.

Williams asked other scientists at NASA. He searched online. Slowly, he started to piece together an incredible story—one that began in the 1970s. 

Back then, space travel was still new. And scientists were starting to figure out how being in space would affect humans. 

Space is completely different from Earth. Here on Earth, gravity pulls you down toward the ground. In space, there’s very little gravity, so everything floats. Over time, low gravity can weaken your bones and muscles. In space, you are also hit by more radiation from the sun. Too much radiation can harm your body by affecting how it works and grows.

But in the 1970s, no one knew how space might affect other living things, like trees. Trees only grow on Earth. So scientists had a lot of questions. What would happen if we launched seeds into space? Would they survive the trip in low gravity? Would the extra radiation cause the seeds to grow into completely different types of trees?

Someone at NASA wanted to find the answers.

Williams asked other scientists at NASA. He searched online. Slowly, he found out about an amazing story. It began in the 1970s. 

Back then, space travel was still new. Scientists were starting to learn how being in space would affect humans. 

Space is very different from Earth. On Earth, gravity pulls you down toward the ground. There’s very little gravity in space, so everything floats. Over time, low gravity can weaken your body. In space, you are also hit by more radiation from the sun. Too much radiation can harm your body. 

In the 1970s, no one knew how space might affect other living things, like trees. Trees only grow on Earth. So scientists had a lot of questions. What would happen if we sent seeds into space? Would they survive the trip? Would the seeds grow into different types of trees? 

Someone at NASA wanted to find the answers

That someone was a tree-loving astronaut named Stuart Roosa. Roosa didn’t just love trees. He fought for them. After high school, he became a smokejumper. That’s a special type of firefighter who parachutes out of planes to battle fires in faraway forests. 

Roosa also loved flying. And he dreamed of flying higher than most people had ever been: to space. In 1966, he joined NASA as an astronaut.

A few years later, NASA chose Roosa to pilot a spaceship that would fly all the way to the moon. There were two other astronauts on the spaceship. And each was allowed to bring something they found meaningful in a wallet-sized container.

Astronauts usually packed things like family photos or small flags for their journey to the moon. What did Roosa bring? Out of everything that he could have taken from Earth, he chose to take about 500
tree seeds.

That someone was a tree-loving astronaut named Stuart Roosa. Roosa didn’t just love trees. He fought for them. After high school, he became a smokejumper. That’s a special type of firefighter who jumps out of planes to put out forest fires. 

 Then in 1966, Roosa joined NASA as an astronaut. 

A few years later, NASA chose Roosa to pilot a spaceship that would fly to the moon. There were two other astronauts on the spaceship. Each was allowed to bring something special to them in a small container. 

Astronauts usually packed things like family photos or small flags. But what did Roosa bring? About 500 tree seeds.

With the help of scientists, Roosa collected the seeds from five types of trees growing in the U.S. Some were redwood seeds, which can grow into giant trees as tall as a 40-story skyscraper. Others were Douglas fir, a type of pine tree often used as Christmas trees. And then there were sycamore seeds.

The tiny seeds were sealed inside a fireproof metal box and stashed safely inside the spaceship. Then, on January 31, 1971, it was time to launch. 

3, 2, 1 . . . Liftoff! 

The spaceship shot into the sky—faster and faster, higher and higher. Soon Roosa and his little seeds were all floating in space, headed straight to the moon. The 240,000-mile trip took four days. 

Roosa didn’t actually get to walk on the moon. His job was to stay on board the spaceship while the other astronauts explored the moon. He had to make sure their spaceship stayed safe for the return trip.

And so Roosa waited. And the seeds waited with him. Roosa and the seeds flew around the moon for 35 hours before returning back home—to planet Earth.

Roosa collected the seeds from five types of trees that grow in the U.S. Some were redwood seeds. They can grow into big trees as tall as a 40-story skyscraper. Others were Douglas fir. They are a type of pine tree often used as Christmas trees. And then there were sycamore seeds. 

The tiny seeds were packed safely inside the spaceship. Then, on January 31, 1971, it was time to launch. 

3, 2, 1 . . . Liftoff! 

The spaceship shot into the sky. Soon Roosa and his little seeds were all floating in space, headed straight to the moon. The 240,000-mile trip took four days. 

Roosa’s job was to stay on board the spaceship while the other astronauts explored. He had to make sure their spaceship stayed safe for the return trip. 

So Roosa flew around the moon for 35 hours before returning to Earth with the seeds.

Once Roosa and the other astronauts got back, the science could begin! Experts planted the seeds in soil. They watered them. They bathed them in warm sunlight. 

Slowly, the seeds started growing. They broke through the soil and began unfurling into tiny saplings. Of the 500 seeds, more than 400 began growing into plants. The seeds had survived the trip in space!

But would the plants grow differently after their journey to the moon? It would take a long time to find out. Trees take years and years to grow. Some redwood trees can grow for more than 2,000 years—much longer than people live. 

So to keep the science experiment going, the saplings were planted all over the U.S. One ended up at the White House. Others were placed in front of elementary schools in Idaho, Pennsylvania, and Virginia. Some were planted in private backyards. Still others were gifted to countries around the world, like Brazil and Japan. 

People sometimes put a sign in front of the trees. The signs gave the plants a special name: Moon Trees.

Back on Earth, the science began! Experts planted the seeds in soil. They watered them. They put them in warm sunlight. 

Slowly, the seeds started growing into tiny saplings. Out of 500 seeds, more than 400 grew into plants. The seeds had survived their trip in space! 

But would the plants grow differently after their journey to the moon? It
would take a long time to find out. Trees take years and years to grow. Some redwood trees can grow for more than  2,000 years. That’s much longer than people live. 

The saplings were planted all over the U.S. One ended up at the White
House. Some were placed in front of elementary schools in Idaho, Pennsylvania, and Virginia. Several were planted in private backyards. Others were gifted to countries around the world, like Brazil and Japan.

People sometimes put a sign in front of the trees. They gave the plants a special name: Moon Trees.

Over time, the Moon Trees kept doing what trees do. Their roots sucked water and other nutrients from the soil. Their branches stretched toward the sky. Their leaves sprouted, fell, and then sprouted again. 

Year after year after year.

But as time passed—and the trees kept growing—people began to forget about the trees. Roosa’s science experiment was mostly lost to memory. That is, until that third-grader in Indiana spotted the Moon Tree in 1996 and told her teacher, Joan Goble. 

After Dave Williams at NASA received Ms. Goble’s email and learned about the Moon Trees, he put up a website. He asked people to let him know if they’d seen other Moon Trees in their neighborhoods. He started receiving emails from all over the U.S. 

So far, more than 100 Moon Trees have been found.

Over time, the Moon Trees continued to grow. But as time passed, people began to forget about the trees and Roosa’s science experiment. That is, until that third-grader spotted a Moon Tree in 1996 and told her teacher, Joan Goble. 

After Dave Williams at NASA received Ms. Goble’s email about the Moon Trees, he created a website. It asked people to let him know if they’d seen other Moon Trees in their neighborhoods. He started receiving emails from all over the U.S. 

So far, more than 100 Moon Trees have been found.

So what happened to the Moon Trees? Those that have been discovered seem to be growing just fine—as if they’d never been to space. Some have died, as trees naturally do. Others have produced seeds of their own. Scientists at NASA have collected some of those seeds and planted them. (The space agency calls them “Half-Moon Trees.”)

But dozens of Moon Trees are still missing. No one knows where they are or how they’re growing. So if you walk around, pay attention to the trees around you. Is there a sign in front? Take a closer look. You might just find . . . a Moon Tree. 

So what happened to the Moon Trees? Those that we know about seem to be growing just fine. It was like they had never been to space. Some have died. Others have produced seeds of their own. Scientists at NASA have collected some of those seeds and planted them. These new trees are called “Half-Moon Trees.” 

But dozens of Moon Trees are still missing. No one knows where they are or how they’re growing. So if you walk around, pay attention to the trees around  you. Is there a sign in front?  Take a closer look. You might just find . . .  a Moon Tree.