Possible Clues:

• Mars, e.g.
• Satellite of a sun
• Such a red aircraft would begin to take one to Mars
• One of these can be found reading counterclockwise somewhere in each concentric ring
• Krypton or Vulcan
• Chart alien from whence he came?
• Mercury, say, showing temperature on aircraft
• There's a little way inside for its orbit
• Astronomer's sighting
• Evening star, e.g.