Above is an image, taken by NASA's Juno spacecraft of the asterism known in the U.S. as the "Big Dipper." Image Credit: NASA/JPL-Caltech/SWRI/MSSS
The above image is an asterism -- a grouping of stars that is not an official constellation, but is still familiar to observers. The grouping is called different names by different people. For example, it is called the "Big Dipper" (US), the "Plough" (UK), the "Great Cart" (Germany), and "Seven Ploughs" (Malaysia).
Whatever the name, these stars have long been, for northern hemisphere observers, a welcome and familiar introduction to the heavens. Now, these stars are helping the Juno mission team make sure that Juno's camera is ready to do its job.
Launched on August 5, 2011, the solar-powered Juno spacecraft is about 380 million miles (612 million kilometers) into its five-year, 1,905-million-mile (3,065-million-kilometer) journey to Jupiter. Once there, the spacecraft will orbit the planet's poles 33 times and use its nine instruments to image and probe beneath the gas giant's obscuring cloud cover to learn more about Jupiter's origins, structure, atmosphere and magnetosphere, and look for a potential solid planetary core.
The instrument tasked with taking closeups of Jupiter's atmosphere is the JunoCam. But it would be four-and-a-half years until JunoCam's CCD (charged-coupled device) actually saw Jupiter. So the mission planners needed something on which to certify the instrument and they decided on this familiar grouping of stars. On March 21, JunoCam took the image seen above. The Juno team was thrilled by the result and is confident that the instrument is ready for Jupiter.
You can view the full test image online at: photojournal.jpl.nasa.gov/catalog/PIA15653
Juno's name comes from Greek and Roman mythology. The god Jupiter drew a veil of clouds around himself to hide his mischief, and his wife, the goddess Juno, was able to peer through the clouds and reveal Jupiter's true nature.
And now, the mission particulars...
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. JunoCam was developed and is operated by Malin Space Science Systems in San Diego. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of the California Institute of Technology in Pasadena.
Learn more about Juno online at www.nasa.gov/juno and missionjuno.swri.edu .