Space: there's a whole lot of it. But if you want a spacecraft
to stick around your celestial neighborhood, there are only five
places to consider. Lagrange points are locations in space where
objects sent there tend to stay put. A French-Italian
mathematician named Joseph-Louis Lagrange, born in 1736,
mathematically hypothesized their existence during his study of
planetary physics. Lagrange believed that in a two-body system,
such as Earth and the sun, there would be points nearby where an
third object could be positioned and remain in place relative to
the other two objects.Lagrange point 1, or L1, is located about
4 times farther from Earth than the moon. Click on the image for
a diagram of all five Earth-Sun Lagrange points. Typically, a
spacecraft sent from the Earth into the vacuum of space will
continue moving in the direction we send it, unless it's
affected by the gravity of a celestial object, like a star or a
planet. Even if we stopped a spacecraft in the middle of space,
the gravity of objects ar