Skip Navigation: Avoid going through Home page links and jump straight to content
spacer spacer spacer
spacer spacer spacer
spacer
NASA Logo    + View the NASA Portal  
Near Earth Object Program
spacer
spacer spacer spacer
spacer
NEO Basics Search Programs Discovery Statistics Accessible NEAs News Frequently Asked Questions
spacer
spacer spacer spacer
spacer
Orbit Diagrams Orbit Elements Close Approaches Impact Risk Images Related LInks
spacer
spacer spacer spacer
spacer

NOTICE: JPL's Center for NEO Studies (CNEOS), which operates neo.jpl.nasa.gov, will substantially upgrade the site in early 2017, giving it a new look-and-feel, improved navigation and added content. Scripts which extract data from HTML on the current site will have to be revised to use the related API on the new site. Specifics on the new APIs will be provided here a month before the site transition takes place.

The Follow-up Observing Programs
Once a NEO is discovered, follow-up astrometric observations are required to improve the orbital predictions so that the object is not lost to future observing attempts. Most of the NEO Discovery Surveys, including the Catalina Sky survey, Pan-STARRS and Spacewatch provide a substantial number of follow-up observations. Dr. David Tholen, at the University of Hawaii, is particularly efficient in providing the very faint follow-up observations that are often required to prevent small NEOs from being lost. A substantial number of faint follow-up observations are also made at the Magdalena Ridge Observatory in New Mexico (Bill and Eileen Ryan). Explicit mention should also be made of the prolific number of follow-up observations provided by the Astronomical Research Institute (ARI) under the direction of Robert Holmes and the amateur group at the New Millennium Observatory in Northern Italy.

Once an object has been discovered with optical telescopes and a preliminary orbit established, radar observations (Doppler and range) are often possible and these very powerful measurements can be used to rapidly secure the object's orbit and often allow accurate, long-term extrapolations of the object's trajectory well into the future. Radar observations are also useful for physically characterizing the object's size, shape, rotation characteristics, its roughness and whether it has a moon (or moons).

For more information, see:

http://www.lpl.arizona.edu/css/ (Catalina Sky Survey)
http://pirlwww.lpl.arizona.edu/spacewatch/ (Spacewatch)
http://pan-starrs.ifa.hawaii.edu/public/ (Pan-STARRS)
http://www.mro.nmt.edu (Magdalena Ridge Observatory)
http://www.astro-research.org (Astronomical Research Institute)
http://www.webalice.it (New Millennium Observatory)
http://echo.jpl.nasa.gov (JPL radar observation activities)

Menu
  NASA Home Page Site Manager: Paul Chodas
Webmaster: Ron Baalke
Last Updated:
Feedback Credits Privacy Mailing List NASA