The New Yorker, 3/13
In March, 2002, NASA and the Deutsches
Zentrum für Luftund Raumfahrt, the German aerospace agency, launched a
pair of satellites from the Plesetsk Cosmodrome, a former
intercontinental-ballistic-missile site in northern Russia, to map
changes in the earth’s surface. The satellites, nicknamed Tom and
Jerry, have been chasing each other around the globe ever since.
Separated by a gap of approximately a hundred and thirty-seven miles,
they sometimes pull apart, only to draw closer again. By monitoring
their relative positions to the fantastic exactitude of one micron(less
than one-fiftieth the width of a human hair(scientists can detect tiny
variations in the earth’s gravitational field. [read more]