Japan is planning a joint mission with the European Space Agency that would be the first to land a probe on Mercury, a space official said on Wednesday.
The mission entails three probes, two that would orbit and one that would land, to map the topography and study the origins of the closest planet to the sun.
Russian Soyuz rockets would launch the probes in space shots starting in 2010. The probes would reach Mercury about four years later, with one of them landing on the planet, and the other two orbiting and charting its surface for a year.
"This would be the first landing," said Masahiko Sawbe of Japan's education and science ministry. "If successful we will collect a lot of new scientific knowledge"
To escape the searing heat of Mercury's rocky surface, where temperatures hit 467 degrees Celsius in the day, the probe would land on the dark side of the planet during the Mercury night. Temperatures plunge to -183 degrees Celsius then. Because of Mercury's slow rotation around its axis, one day there lasts up to 176 earth days.
Mercury has only been visited by one probe - the US- launched Mariner 10, which conducted three flybys from 1974 to 1975. NASA is planning to launch another orbiting probe, dubbed Messenger, sometime in 2004. It will reach Mercury in 2007.3
For the Mercury venture, Japan would chip in $115 million and Europe would contribute $513 million, Sawabe said. Japan would build one of the orbiting satellites and the Europeans would build the lander and the other orbiter.
The goal of the mission is to study the planet's surface and environment and try to unlock the mysteries of how the planet evolved.