Este fue
tu cielo.

The Smooth Spheres of Gravity Probe B

Does gravity have a magnetic counterpart? According to Einstein, spinning any mass should create a slight effect similar to magnetism. This gravitomagnetism is too small for practical experience or laboratory measurement. However, NASA launched the Gravity Probe B last week, carrying the smoothest spheres ever manufactured. The mission aims to directly measure this subtle effect by observing how these spinning spheres behave in space.