enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. VSOP model - Wikipedia

    en.wikipedia.org/wiki/VSOP_model

    It is customary to develop them into periodic series which are a function of time, e.g. (a+bt+ct 2 +...)×cos(p+qt+rt 2 +...) and so forth, one for each planetary interaction. The factor a in the preceding formula is the main amplitude, the factor q the main angular velocity, which is directly related to a harmonic of the driving force, that is ...

  3. Jet Propulsion Laboratory Development Ephemeris - Wikipedia

    en.wikipedia.org/wiki/Jet_Propulsion_Laboratory...

    The observational data in the fits has been an evolving set, including: ranges (distances) to planets measured by radio signals from spacecraft, [11] direct radar-ranging of planets, two-dimensional position fixes (on the plane of the sky) by VLBI of spacecraft, transit and CCD telescopic observations of planets and small bodies, and laser ...

  4. Two-body problem in general relativity - Wikipedia

    en.wikipedia.org/wiki/Two-body_problem_in...

    In the Schwarzschild solution, it is assumed that the larger mass M is stationary and it alone determines the gravitational field (i.e., the geometry of space-time) and, hence, the lesser mass m follows a geodesic path through that fixed space-time. This is a reasonable approximation for photons and the orbit of Mercury, which is roughly 6 ...

  5. Lunar Laser Ranging experiments - Wikipedia

    en.wikipedia.org/wiki/Lunar_Laser_Ranging...

    The Lunar Laser Ranging data is collected in order to extract numerical values for a number of parameters. Analyzing the range data involves dynamics, terrestrial geophysics, and lunar geophysics. The modeling problem involves two aspects: an accurate computation of the lunar orbit and lunar orientation, and an accurate model for the time of ...

  6. Astronomical coordinate systems - Wikipedia

    en.wikipedia.org/wiki/Astronomical_coordinate...

    Angles in the hours ( h), minutes ( m), and seconds ( s) of time measure must be converted to decimal degrees or radians before calculations are performed. 1 h = 15°; 1 m = 15′; 1 s = 15″ Angles greater than 360° (2 π ) or less than 0° may need to be reduced to the range 0°−360° (0–2 π ) depending upon the particular calculating ...

  7. Orbit determination - Wikipedia

    en.wikipedia.org/wiki/Orbit_determination

    In order to determine the unknown orbit of a body, some observations of its motion with time are required. In early modern astronomy, the only available observational data for celestial objects were the right ascension and declination, obtained by observing the body as it moved in its observation arc, relative to the fixed stars, using an optical telescope.

  8. Kepler's equation - Wikipedia

    en.wikipedia.org/wiki/Kepler's_equation

    As for instance, if the body passes the periastron at coordinates = (), =, at time =, then to find out the position of the body at any time, you first calculate the mean anomaly from the time and the mean motion by the formula = (), then solve the Kepler equation above to get , then get the coordinates from:

  9. Numerical model of the Solar System - Wikipedia

    en.wikipedia.org/wiki/Numerical_model_of_the...

    To calculate the accelerations the gravitational attraction of each body on each other body is to be taken into account. As a consequence the amount of calculation in the simulation goes up with the square of the number of bodies: Doubling the number of bodies increases the work with a factor four.