Flowers from the Ganjoji "space tree" also look a bit different, containing five petals, as opposed to about 30 like their parent trees.
The precocious pips have baffled the Buddhist monks and scientists alike. The project was not primarily a scientific one, rather "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 (JAMSS). For that reason no "control" seeds were planted to contrast with the space-flown ones--although this cherry variety usually doesn't bloom until the age of 10.
The reason for the early flowering is a mystery. One guess is that "exposure to stronger cosmic rays accelerated the process of sprouting and overall growth," said Kaori Tomita-Yokotani, a plant physiologist at the University of Tsukuba who took part in the project. But "from a scientific point of view, we can only say we don't know why," Tomita-Yokotani added.