- vernal equinox frame
- Космонавтика: система весны
Универсальный англо-русский словарь. Академик.ру. 2011.
Универсальный англо-русский словарь. Академик.ру. 2011.
Equinox (celestial coordinates) — In astronomy, equinox is a moment in time at which the vernal point, celestial equator, and other such elements are taken to be used in the definition of a celestial coordinate system. The position at other equinoxes can be computed by taking… … Wikipedia
Sidereal time — is a measure of the position of the Earth in its rotation around its axis, or time measured by the apparent diurnal motion of the vernal equinox, which is very close to, but not identical to, the motion of stars. They differ by the precession of… … Wikipedia
Zodiac — See also: Zodiac (disambiguation) Wheel of the zodiac: This 6th century mosaic pavement in a synagogue incorporates Greek Byzantine elements, Beit Alpha … Wikipedia
Tropical year — A tropical year (also known as a solar year), for general purposes, is the length of time that the Sun takes to return to the same position in the cycle of seasons, as seen from Earth; for example, the time from vernal equinox to vernal equinox,… … Wikipedia
Precession (astronomy) — In astronomy, precession refers to the movement of the rotational axis of a body, such as a planet, with respect to inertial space. In particular, it refers to the precession of the Earth s rotational axis, also called the precession of the… … Wikipedia
Hebrew calendar — The Hebrew calendar (הלוח העברי ha luach ha ivri), or Jewish calendar, is a lunisolar calendar used today predominantly for Jewish religious observances. It determines the dates for Jewish holidays and the appropriate public reading of Torah… … Wikipedia
Orbital elements — are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are generally considered in classical two body systems, where a Kepler orbit is used (derived from Newton s laws of motion and Newton s law… … Wikipedia
Year — A year (from Old English gēar) is the orbital period of the Earth moving around the Sun. For an observer on Earth, this corresponds to the period it takes the Sun to complete one course throughout the zodiac along the ecliptic. In astronomy, the… … Wikipedia
Epoch (astronomy) — In astronomy, an epoch is a moment in time used as a reference for the orbital elements of a celestial body. [cite book|last=Soop|first=E. M.|title=Handbook of Geostationary Orbits|publisher=Springer|date=1994|isbn=9780792330547] Typically, the… … Wikipedia
Longitude — For Dava Sobel s book about John Harrison, see Longitude (book). For the adaptation of Sobel s book, see Longitude (TV series). Map of Earth Longitude (λ) Lines of longitude appear vertical with varying curvature in this projection, but are… … Wikipedia
Earth Centered Inertial — The Earth Centered Inertial (ECI) Frame is a non rotating version of the (ECEF) frame. The ECI frame is identical to the ECEF frame at some instant in time. The ECI frame is a convenient inertial frame for which Newton s second law is valid, and… … Wikipedia