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  2. Earth's orbit - Wikipedia

    en.wikipedia.org/wiki/Earth's_orbit

    Ignoring the influence of other Solar System bodies, Earth's orbit, also called Earth's revolution, is an ellipse with the EarthSun barycenter as one focus with a current eccentricity of 0.0167. Since this value is close to zero, the center of the orbit is relatively close to the center of the Sun (relative to the size of the orbit).

  3. Ecliptic - Wikipedia

    en.wikipedia.org/wiki/Ecliptic

    The orientation of Earth's axis and equator are not fixed in space, but rotate about the poles of the ecliptic with a period of about 26,000 years, a process known as lunisolar precession, as it is due mostly to the gravitational effect of the Moon and Sun on Earth's equatorial bulge. Likewise, the ecliptic itself is not fixed.

  4. Orbit of the Moon - Wikipedia

    en.wikipedia.org/wiki/Orbit_of_the_Moon

    The Sun's gravitational effect on the Moon is more than twice that of Earth's on the Moon; consequently, the Moon's trajectory is always convex [25] [26] (as seen when looking Sunward at the entire SunEarthMoon system from a great distance outside EarthMoon solar orbit), and is nowhere concave (from the same perspective) or looped.

  5. Solar eclipse - Wikipedia

    en.wikipedia.org/wiki/Solar_eclipse

    A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby obscuring the view of the Sun from a small part of Earth, totally or partially.Such an alignment occurs approximately every six months, during the eclipse season in its new moon phase, when the Moon's orbital plane is closest to the plane of Earth's orbit. [1]

  6. Kepler's laws of planetary motion - Wikipedia

    en.wikipedia.org/wiki/Kepler's_laws_of_planetary...

    The Sun (located at the focus) is labeled S and the planet P. The auxiliary circle is an aid to calculation. Line xd is perpendicular to the base and through the planet P. The shaded sectors are arranged to have equal areas by positioning of point y. The Keplerian problem assumes an elliptical orbit and the four points: s the Sun (at one focus ...

  7. Orbital period - Wikipedia

    en.wikipedia.org/wiki/Orbital_period

    For example, the synodic period of the Moon's orbit as seen from Earth, relative to the Sun, is 29.5 mean solar days, since the Moon's phase and position relative to the Sun and Earth repeats after this period. This is longer than the sidereal period of its orbit around Earth, which is 27.3 mean solar days, owing to the motion of Earth around ...

  8. Elliptic orbit - Wikipedia

    en.wikipedia.org/wiki/Elliptic_orbit

    In the Solar System, planets, asteroids, most comets, and some pieces of space debris have approximately elliptical orbits around the Sun. Strictly speaking, both bodies revolve around the same focus of the ellipse, the one closer to the more massive body, but when one body is significantly more massive, such as the sun in relation to the earth ...

  9. Eclipse season - Wikipedia

    en.wikipedia.org/wiki/Eclipse_season

    An eclipse season is the only time when the Sun (from the perspective of the Earth) is close enough to one of the Moon's nodes to allow an eclipse to occur. During the season, whenever there is a full moon a lunar eclipse may occur and whenever there is a new moon a solar eclipse may occur.