Cherry stones taken into space have produced fruit trees that bloom six years earlier than trees from stones that never left the planet. Scientists are baffled as to why, but search for answers could prove fruitful in unexpected ways.
In 2008 stones collected by young children from 14 cherry trees across Japan were taken aboard the International Space Station by Japanese astronaut Koichi Wakata, now the station's commander. They orbited the planet 4100 times with him. Some were then tested in laboratories, but most were returned to their homes and planted.
The pacesetter among these stones comes from the famous "Chujo-hime-seigan-zakura" tree in the grounds of the Ganjoji temple in Gifu. When planted in the grounds it grew rapidly to 4m tall and burst into bloom, appropriately enough on April 1. Three other trees whose seeds made the same journey have also blossomed this year.
There were three remarkable features of this. For one thing it is the first time in living memory the monks of the temple have been able to get a stone from the parent tree to sprout. The chief priest Masahiro Kajita told AFP, “We are very happy because it will succeed the old tree, which is said to be 1,250 years old."
Even more surprisingly, cherry trees don't usually bloom four years after being planted. “We had expected the (Ganjoji) tree to blossom about 10 years after planting, when the children come of age," said Miho Tomioka of Japan Manned Space Systems, the organizer of the cherries in space project.
If this wasn't odd enough the trees nine flowers have five petals each. The parental tree's flowers have around 30.
The obvious first thought is that zero gravity may have somehow affected the seed, but Dr Kaori Yokata-Tomita of the University of Tsukuba says that without the successful sprouting of a sibling tree it can't be ruled out that rapid blooming is a feature of the offspring of this tree. Cross pollination with a different species is also a possibility, but Tomita added, "Of course, there is the possibility that exposure to stronger cosmic rays accelerated the process of sprouting and overall growth." She added that the five petal flowers may be a reversion to its ancestral characteristics, or may change as the tree grows.
The temple is different from the one of the same name in Fukashima province, so don't jump to conclusions. The stones came from the yamazakura species of wild cherry grown for ornamental value – they do not produce edible fruit.