In 1877 a woman called Mrs. Gill came to Ascension Island with her husband David. David was an astronomer, a man who studies the stars. People told them about a place called Green Mountain. They looked at the black rocks and the red hills, but they saw no green place. They said to each other: “Nothing green.”
But the mountain was there. Green Mountain is the highest place on Ascension. Today it has a big forest, and people planted almost all of it.
Ascension is a small island in the Atlantic Ocean, between Africa and South America. It is more than 1,500 kilometres from any big land, so very few plants came there alone.
In 1815 British soldiers came to live on the island. They needed water, but there was very little. There was only one spring of fresh water, high on Green Mountain. Mist often covered the top of the mountain, and only there was it green.
In 1843 a young plant scientist, Joseph Dalton Hooker, visited the island. He wanted to put plants all over it. He hoped the plants would bring more rain. Trees and seeds came, and they grew. A report in 1865 said the island now had 40 kinds of trees, and there was now plenty of water.
The Gills wanted to look at the stars, but heavy clouds came from the mountain night after night. One evening a cloud moved in front of Mars. So they moved to Mars Bay, a place on the south coast far from the mountain.
Hooker was probably wrong about the rain. The trees did not bring more rain, but their leaves caught more of the mist. Very small drops of water hit the leaves. They became bigger drops and fell to the ground.
The forest has a problem too. The new plants are a danger to some of the island’s own plants.
Scientists still want to know how much water the mist really gives. They do not have many measurements from these islands. Nearly 150 years after Mrs. Gill watched a cloud cover Mars, they are still studying those clouds.