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Main Features
  • The regularly updated database of comets.
  • Complete database management with possibility of adding your own objects.
  • Fast search on any element of the database.
  • Import/Export from ECS Format.
  • High-precision calculation of small-bodies orbits.
  • High-speed integration of the equations of motion.
  • Visualization of small-bodies orbits.
  • Calculation of orbital evolution of small-bodies.
  • Calculation of moments of perihelion passages.
  • Detection of close approaches with planets.
How Halley works?
The core of Halley software has been implemented in Fortran (Intel ® Fortran Compiler used). This allows to produce high-precision integration of the equations of motion of asteroids and comets. The gravitational perturbations from all major planets and Pluto are taken into account in the equations of motion. Coordinates of the perturbing planets are computed on a basis of JPL Planetary and Lunar Ephemerides. Equations of motion include relativistic perturbations from the Sun. Perturbations of the Earth and Moon are taken into account separately. Marsden's model was taken as a model of non-gravitational accelerations with perihelion-maximum offset parameter. Numerical integration of the equations of motion is performed by Everhart's method of 11-th order with automatic control of step size. High accuracy of numerical integration is achieved through the use of the modified Encke's method. The modification consists of performing the change of the osculation epoch at each step of integration. The parameters of the unperturbed motion are calculated with quadruple precision by using variables with 32 decimals. Database management is performed using the SQLite library.
Operating System
Halley is intended for use with a personal computer with Microsoft Windows ® XP, Vista or 7.