Juno is flying by by the planet Earth on October 9, 2013. Will it be visible to the naked eye anywhere on Earth, and if so, where and when?
This image shows the trajectory of the Juno spacecraft. It can be seen that the closest approach takes place in the shroud of Earth's shadow, so most of the world is going to miss this.
Two minutes before closest approach Juno will experience the only eclipse of its mission, passing into the umbra of Earth’s shadow for about 20 minutes. Chris Peat at Heavens-Above also told Universe Today that observers in India are also well-placed to catch sight of Juno with binoculars after it exits the Earth’s shadow.
You may visit Heavens Above to configure your current location.
The next step is to visit this page on the same site. It renders a map showing your configured location against the Juno Ground-track. The page also renders a table to guide your observation of the spacecraft in the skies.