A cosmic mystery is uniting monks and scientists after a cherry tree grown from a seed that orbited the Earth for eight months bloomed years earlier than expected — and with an unusual number of flowers.
The four-year-old sapling — grown from a cherry pit that spent time aboard the International Space Station — burst into blossom on April 1, possibly a full six years ahead of Mother Nature’s normal schedule.
Its early blooming baffled Buddhist brothers at Ganjoji Temple in Gifu Prefecture, where the tree was planted.
“We are amazed to see how fast it has grown,” Masahiro Kajita, the temple’s chief priest, said.
“A stone from the original tree had never sprouted before. We are very happy because it will succeed the old tree, which is said to be 1,250 years old.”
The wonder stone was among 265 harvested from the celebrated “Chujo-hime-seigan-zakura” tree, selected as part of a project to gather seeds from different kinds of cherry trees at 14 places across Japan.
The stones were sent up to the ISS in November 2008 and came back to Earth in July the following year with Japanese astronaut Koichi Wakata, after circling the globe 4,100 times.
Some were sent for laboratory tests, but most were returned to their places of origin, and a selection was planted at nurseries near Ganjoji temple.
By April this year, the “space cherry tree” had grown to around four meters tall and suddenly produced nine flowers, each with the normal five petals, compared with about 30 flowers on the parent tree.
It normally takes about 10 years for a cherry tree of a similar variety to bear its first buds.
The Ganjoji temple sapling is not the only early-flowering space cherry tree. Of the 14 places where orbited pits were replanted, blossoms have been spotted in four.
Two years ago, a young tree bore 11 flowers in Hokuto, Yamanashi Prefecture, a mountainous region 115 km west of Tokyo, around two years after it was replanted. That tree was of a variety that normally only flowers at the age of eight.
The seeds were sent to the ISS as part of “an educational and cultural project to let children gather the stones and learn how they grow into trees and live on, after returning from space,” said Miho Tomioka, a spokeswoman for the project’s organizer, Japan Manned Space Systems.
“We had expected the (Ganjoji) tree to blossom about 10 years after planting, when the children come of age,” she added.
Kaori Tomita-Yokotani, a researcher at the University of Tsukuba who took part in the project, said she was stumped by the extraterrestrial mystery.
“We still cannot rule out the possibility that it has been somewhat influenced by its exposure to the space environment,” she said.
Tomita-Yokotani, a plant physiologist, said it is difficult to explain why the temple tree has grown so fast because there was no control group to compare its growth to.
She said cross-pollination with another species could not be ruled out, but a lack of data is hampering an explanation.
“Of course, there is the possibility that exposure to stronger cosmic rays accelerated the process of sprouting and overall growth,” she said.
“From a scientific point of view, we can only say we don’t know why.”