- published: 15 Apr 2015
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In astrodynamics or celestial mechanics an elliptic orbit is a Kepler orbit with the eccentricity less than 1; this includes the special case of a circular orbit, with eccentricity equal to zero. In a stricter sense, it is a Kepler orbit with the eccentricity greater than 0 and less than 1 (thus excluding the circular orbit). In a wider sense it is a Kepler orbit with negative energy. This includes the radial elliptic orbit, with eccentricity equal to 1.
In a gravitational two-body problem with negative energy both bodies follow similar elliptic orbits with the same orbital period around their common barycenter. Also the relative position of one body with respect to the other follows an elliptic orbit.
Examples of elliptic orbits include: Hohmann transfer orbit, Molniya orbit and tundra orbit.
Under standard assumptions the orbital speed () of a body traveling along an elliptic orbit can be computed from the Vis-viva equation as:
where:
With his first law of planetary motion, Kepler rejected circular orbits and showed that an ellipse could better explain the observed motions of Mars. Generalized to all planets, it states that the orbit of a planet follows an ellipse with the Sun at one focus. Kepler's 1st Law: http://bit.ly/1XCVRSQ Kepler's 2nd Law:http://bit.ly/1lzhLVQ Kepler's 3rd Law: http://bit.ly/1MZ35bR Please Subscribe, and share with your friends! http://bit.ly/1ixuu9W Presented by Liliana de Castro Written by Meg Rosenburg Produced by Kimberly Hatch Harrison & Michael Harrison
Paul distinguishes circular and elliptical orbits with force vectors for each.
An introduction into elliptical orbits and the conservation of angular momentum. This is at the AP Physics level or the introductory college level physics level.
Elliptical Orbit of Planets can be explained using a spherical Pendulum. In this video Dr. D explains elliptical orbits, precession and the Planet Mercury using a spherical pendulum and some good old fashioned physics. Let us know what you think and click the subscribe button why you're at at.
Of all the possible shapes, why do all planets orbit stars in ellipses? This is known as Kepler's 1st Law of Planetary Motion, but why is it true? Using Newton's laws of gravity and motion, Ryan MacDonald - a Theoretical Astrophysicist based at Cambridge University - proves from first principles Kepler's laws of planetary motion (Part 1 of 2)
Uploaded for a blog post on the Antikythera Mechanism at http://alunsalt.com/2010/05/14/planets-and-anomalies-in-the-antikythera-mechanism Cogs move in circles, but planets don't. Kepler found that small errors in Copernicus' model of the solar system could be solved if the planets moved in ellipses. For Earth the ellipse is so slight that it's only fractionally off a circle. Yet even this fraction could be observed by the ancient Greeks because a planet moves faster when it's closer to a star. But how do you simulate elliptical motion if you only have circular cogs? The animation was made with the excellent My Solar System 2.02 at http://phet.colorado.edu/sims/my-solar-system/my-solar-system_en.html For more info on Planetary Motion search for Kepler's Laws. http://www.youtube.co...
Kepler's Laws, Elliptical Orbits, Change of Orbits, and the famous passing of a Ham Sandwich. Kepler's three Laws summarize the motion of the planets in our solar system. Following Newton's law of universal gravitation, the conservation of angular momentum and mechanical energy allow us to calculate the semimajor axis of the elliptical orbits, the orbital period and other orbital parameters. All we have to know is one position and the associated velocity of a planet and the entire orbit follows. This lecture is part of 8.01 Physics I: Classical Mechanics, as taught in Fall 1999 by Dr. Walter Lewin at MIT. This video was formerly hosted on the YouTube channel MIT OpenCourseWare. This version was downloaded from the Internet Archive, at https://archive.org/details/MIT8.01F99/. Attribution...
In general, planets travel in elliptical orbits. The velocity vector is always tangent to the path. The acceleration vector will have both centripetal and tangential components, so its direction changes relative to the path as the planet orbits.
Nibiru's orbit around the Sun is highly elliptical, according to Sitchin's books, taking it out beyond the orbit of Pluto at its farthest point and bringing it as close to the Sun as the far side of the asteroid belt (a ring of asteroids that is known to occupy a band of space between the orbits of Mars and Jupiter). It takes Nibiru 3,600 years to complete one orbital journey, and it was last in this vicinity around 160 B.C.E. As you can imagine, the gravitational effects of a sizable planet moving close to the inner solar system, as it is claimed for Nibiru, could wreak havoc on the orbits of other planets, disrupt the asteroid belt and spell big trouble for planet Earth.