When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. GJ 1214 b - Wikipedia

    en.wikipedia.org/wiki/GJ_1214_b

    While no scientist has stated to believe GJ 1214 b is an ocean planet, if GJ 1214 b is assumed to be an ocean planet, [22] i.e. the interior is assumed to be composed primarily of a water core surrounded by more water, proportions of the total mass consistent with the mass and radius are about 25% rock and 75% water, covered by a thick envelope ...

  3. SPICE (observation geometry system) - Wikipedia

    en.wikipedia.org/wiki/SPICE_(observation...

    SPICE (Spacecraft Planet Instrument C-matrix Events) is a NASA ancillary information system used to compute geometric information used in planning and analyzing science observations obtained from robotic spacecraft. It is also used in planning missions and conducting numerous engineering functions needed to carry out those missions.

  4. Astronomical coordinate systems - Wikipedia

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

    In astronomy, coordinate systems are used for specifying positions of celestial objects (satellites, planets, stars, galaxies, etc.) relative to a given reference frame, based on physical reference points available to a situated observer (e.g. the true horizon and north to an observer on Earth's surface). [1]

  5. Jet Propulsion Laboratory Development Ephemeris - Wikipedia

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

    The models consist of numeric representations of positions, velocities and accelerations of major Solar System bodies, tabulated at equally spaced intervals of time, covering a specified span of years. [1] Barycentric rectangular coordinates of the Sun, eight major planets and Pluto, and geocentric coordinates of the Moon are tabulated.

  6. Position angle - Wikipedia

    en.wikipedia.org/wiki/Position_angle

    The concept of the position angle is inherited from nautical navigation on the oceans, where the optimum compass course is the course from a known position s to a target position t with minimum effort. Setting aside the influence of winds and ocean currents, the optimum course is the course of smallest distance between the two positions on the ...

  7. List of satellite pass predictors - Wikipedia

    en.wikipedia.org/wiki/List_of_satellite_pass...

    [1] [2] Linked from both NASA and ESA websites as a reference for locating satellites and spacecraft. [3] Includes predictions for the ISS, space shuttle and other bright satellites, planets, minor planets, and comets. JPass, a java based web application. Offline since April 2010, replaced by NASA Skywatch web application. [4]

  8. Orrery - Wikipedia

    en.wikipedia.org/wiki/Orrery

    A small orrery showing Earth and the inner planets. An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not ...

  9. Ephemeris - Wikipedia

    en.wikipedia.org/wiki/Ephemeris

    In astronomy and celestial navigation, an ephemeris (/ ɪ ˈ f ɛ m ər ɪ s /; pl. ephemerides / ˌ ɛ f ə ˈ m ɛr ɪ ˌ d iː z /; from Latin ephemeris 'diary', from Ancient Greek ἐφημερίς (ephēmerís) 'diary, journal') [1] [2] [3] is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position ...