Precision Pointing: It's a Matter of Scale

NASA: Kepler News and Features: For four years, the Kepler spacescraft continuously and simulatenously observed and collected data on more than 150,000 stars. Its mission-- to determine if Earth-size planets orbiting in the habitable zone of stars like our sun are common or rare. The stability of Kepler's pointing is measured in degrees, arcminutes, arcseconds and milli-arcseconds. To put that into perspective, the image compares the measurements using a movie theatre screen, a small bag of popc...