Magnetic mirror on the floor...

A spinning puddle of mercury in a bowl would be an almost perfect reflector for a telescope on the moon. But, they have a major drawback, they can only point straight up, which limits the range of sky that might be observed with such a telescope. Denis Brousseau at Université Laval in Quebec reckons strong magnetic fields could be the answer. Unfortunately, they would have to be incredibly strong to control mercury at anything but horizontal, so the team has turned to nanotechnology and suspended tiny ferromagnetic particles in oil on to which a thin highly reflective layer of silver particles can be spread to create a magnetic mirror that could stand up to closer observations. It would also weight a lot less than a mercury telescope and so would make transportation to our lunar companion a lot less costly.