what are the foci of Earth's elliptical orbit?
605247
the Sun and another point where there is no object
777030
The orbit the moon makes around the earth is not an exact circle, but an ellipse.\n\nThe perigee [or closest approach to earth] = 363,104 km\nThe apogee [or furthest distance to earth] = 405,696 km\n\nThe time it takes for the moon to complete one orbit around the earth is 27 days, 7 hours, and 43.1 minutes.\n\nHope this helps!
104516
By carefully and meticulously studying their orbits and taking note of their positions in the sky night after night for many many years. This work begun with the invention of the telescope but it wasn´t until Johannes Kepler got his hand on all that work, including the work of his mentor Tycho Brahe, that the elliptical nature of planetary motion was discovered. Until then planets were thought to be moving in perfect circles for many resons except scientific. The circle was a nice and harmonic shape. But Kepler, with all those measurments at his hands, couldn´t fit the circle into his charts and models. He thought for years about what other geometrical shapes could fit it and eventually thought to try the ellips. And it fit in (almost) perfectly. From that breakthrough he was able to come up with simple mathematical explanations for planetary motion, now dubbed Kepler´s laws. Isaac Newton later expanded on those laws and the result were Newtons laws. Kepler published his work in 1609 in a book called New Astronomy. (Some errors in Keplers laws could not be explained and corrected until Albert Einstein introduced his work on the space/time relation.)
478701
Equatorial diameter 6,804.9 km (4228.4 Miles)\n(0.533 Earths)\nPolar diameter 6,754.8 km (4197.2 Miles)\n(0.531 Earths)\nOblateness 0.007 36\nSurface area 1.448×108 km2 (55.907 Million Square Miles)\n(0.284 Earths)\n\n\n"Mars-5-inch-thing" Sure... but in which category of questions are we?
166937
check out http://www.answers.com/center%20of%20earth
1153461
It depends on what time period you're talking about. The eclipitic -- the plane of the Earth's orbit -- is tilted from the equator by 23.5 degrees. An object exactly on the ecliptic (like the Sun) reaches its farthest northern point when it's ecliptic longitude is 90 degrees, which happens (for the Sun) on about June 21 every year.\n\nThe Moon's orbit is pretty near the ecliptic, and it also reaches a farthest north point once a month, which occurs when the Moon's ecliptic longitude is at or near 90 degrees. The date on which this occurs, however, varies from one month to the next. In June, it occurs at about the time of the New Moon; in September, at about the time of the third quarter moon; in December, it occurs at about the time of the Full Moon; and in April, at about the time of the first quarter.\n\nBut if you want to take a longer view, we have to account for the fact that the Moon's orbit isn't exactly on the ecliptic: its orbit is inclined to the ecliptic by 5 degrees. The points at which the Moon's orbit crosses the ecliptic are called "nodes" and there are two of them: the ascending node (where the Moon crosses the ecliptic on its way north) and the descending node (where the Moon crosses the ecliptic on its way south). But the positions of the nodes themselves rotate slowly around the ecliptic from one month to the next; it takes about 19 years for the nodes to make a complete circuit of the ecliptic.\n\nNow zero degrees ecliptic longitude (or the "first point of Aries") is the point where the ecliptic crosses the equator on its way north. If the ascending node of the Moon's orbit were exactly at this point too -- which happens once every 19 years -- then the Moon's orbit would be at a point where it would reach an absolute maximum north and south points. \n\nIt just so happens that the Ascending Node reaches the first point of Aries on June 20 2006; and the Moon will reach its farthest north point at 8:40 UT on June 25 2006, when it will be at 28.445 degrees north of the equator. It will not be that far north again for another 19 years!
350355
Earth is an oblate spheroid, resembling a sphere flattened at the poles.\n\nThe volume of an oblate spheroid is\n\n    V = 4/3 X 3.14 X a^2 X b\n\nwhere π is the mathematical constant pi, and a and b are the equatorial and polar radii.\n\nSubstituting a = 6,378,135 m and b = 6,356,750 m\n\nThe Huge EarthThe mean radius of the earth is approximately 6.4 million meters (exact = 6.37 x 106 m). Its volume is then:\n\n(4/3) x 3.14 x 64000003 m3\n\nThis comes to 1,097,509,500,000,000,000,000 cubic meters.
428765
here's a topographical map of the entire planet:\n\nhttp://www.fourmilab.ch/cgi-bin/uncgi/Earth/action?opt=-p&img=NOAAtopo.evif
196821
The plane formed by the Earth's orbit is called the ecliptic. While most of the planets' orbits are close to this plane, Mercury and Pluto's orbits differ by several degrees.
397113
sphere, elliptic, plane, euclidean, pseudosphere, hyperbolic
655853
Precession! The shape of Earth’s orbit becomes more or less oval (eccentricity), Earth wobbles as it spins (precession), and Earth's axis changes too (tilt). All these changes, over thousands of years, causes Earth's climate to change.
1071951
NASA/JPL lists a detailed ephemeris for this object with celestial coordinates ==> http://neo.jpl.nasa.gov/cgi-bin/db_shm?sstr=2004%20XP14
151096
There are two types of satellites: polar and geostationary. Polar satellites circle the earth, covering the north pole and the south pole on every circle, at an altitude of about 850 km. A geostationary satellite "moves with the earth" and is always situated over the same place over the equator, at an altitude of about 36000 km.
922163
On average the sun moves about 1 degree against the background stars per day (that's about 2 full moons!).  Since the Earth is on an elliptical orbit, we actually speed up and slow down, so it changes from day to day the exact amount.  \n\nIf you mean how many degrees above or along your local horizon, you need to give me your latitude and longitude to answer that.
224099
It's not that strange, why would you expect the Earth's orbit to be a perfect circle.\n\nEverything revolve in a elliptical orbit, because they can't all start moving in perfect circles, that's impossible, so when Earth got closer to the Sun, it basically falls and accelerates because of gravity, but because it's now faster, it can bypass the Sun so it won't crash into it.
1097752
north ,south, east and west are compass directions\n \ndown is toward the center of the earth\n\nup is toward space
754835
The axis of earth is tilted 23.45 degree from the ecliptic; and the orbit of the earth around the sun is not a perfect circle (it is an ellipse, and thus the distance from earth to the sun changes over the course of a year)