Once it had been lowered over the side, the robot explorer could send its images and information back through a fibre-optic cable not much thicker than the lead of a pencil.

Scientists also say the Dante mission will give humans experience in controlling robot explorers at a distance, a prelude to similar missions on the moon and other planets.

Obviously, scientists say, robot explorers could be as useful on Earth as they are in space.

Even robot explorers, if we had any, might not survive the radiation.

The clouds and atmosphere of Venus have now become transparent to us, and another world has been visited by the doughty robot explorers from Earth.

But whether in single launches or in pairs, the space-faring nations have clearly decided that the time is ripe to return robot explorers to Mars.

This is not why we explore Mars, but clearly we will need robot explorers to return the real reality before it can be reconfigured into virtual reality.

Everybody knew you could rent time on the lunar robot explorers puttering around the Moon.

Before this story is twice its present age, we will have robot explorers dotted all over Mars.

In the foreseeable future ... we shall be able to build robot explorers that can head to the stars, as our present ones are heading to Mars and Venus.