Asteroids can be analytically separated by the dynamical parameters semi-major axis (a),
inclination (i), and eccentricity (e). In the case of PHAs the
Minimum Orbital
Intersection Distance (MOID) value is also considered.
astorb.dat and astorb.dat.gz have permanently moved to
https://ftp.lowell.edu/pub/elgb/astorb.dat
and https://ftp.lowell.edu/pub/elgb/astorb.dat.gz,
respectively. FTP access is no longer supported.