Every page has a context sensitive "help" link at the top-right of the page. This is the place to look for an explanation of the data and terminology you see on a particular page. The NEODyS HELP system currently offers information on the following topics:

• Additional notes
• Close approaches
• Orbital information
• Ephemerides prediction
• Ephemerides prediction results
• Impactor table
• MJD conversion tables
• NEA elements
• Object home page
• Object list
• Observations
• Observation prediction
• Observation prediction results
• Orbit animation
• Past impactors
• Physical information
• Proper elements
• Related sites
• Risk list
• Risk notes
• Risk page
• Risk references
• Search page
• Search results
• Observatory home page
• Observatory list
• Stationary points
• Priority lists
• Follow-up ranking
• Opportunities