Direct motion
From LoveToKnow 1911
DIRECT MOTION, in astronomy, the apparent motion of a body .
Direct motion- the movement of a celestial body from west to east - that is, in the same direction as that of the Earth around the sun
Disk- the visible surface of the Sun (or any heavenly body) projected against the sky ...
Direct motion Another term for prograde motion.
Dobsonian Named for John Dobson, who originated the design. An altazimuth mount constructed usually of plywood or MDF suited to home construction. Also refers to a telescope so mounted.
Direct motion. Movement of revolution or rotation of a celestial object in the same sense as that of the Earth. For example, the Sun moves across the sky each day from east to west, an effect of the Earth's rotation on its axis.
Direct Motion - The eastward apparent motion of a solar system body with respect to the stars. Direct motion is interrupted by regular episodes of retrograde (westward) motion ...
Direct Motion
(a) Motion of a solar-system body from west to east across the sky.
Direct motion
Objects moving around the Sun in the same direction as the Earth are moving in direct motion, objects moving in the opposite direction are moving in retrograde motion.
Diurnal motion ...
Direct motion is "normal" motion. It is eastward (west to east) and increases right ascension.
Retrograde motion is "backwards" motion. It is westward (east to west) and decreases right ascension.
direct motion (NASA SP-7, 1965) Eastward or counterclockwise motion of a planet or other object as seen from the North Pole (motion in the direction of increasing right ascension). direct product (NASA SP-7, 1965) = scalar product.
(official IAU definition dated 24 August 2006) prograde direct motion proper motion the apparent angular motion across the sky of an object relative to the solar system
Q ...
This philosophy had no problem with the direct motion of the planets, since that could be explained by uniform circular motion of the planets about the Earth (which, as any fool who looked at the sky could see, was clearly the center of the Universe).
Prograde motion is the motion of a planetary body in a direction similar to that of other bodies within its system, and is sometimes called direct motion, especially in astrology. Retrograde motion is motion in the contrary direction.
A small, relativistic, direct motion of the equinox along the ecliptic, amounting to 1".915 per century. [H76]
Geoid ...
The initial direct (easterly) motion up to May 29 is shown in blue, the retrograde motion up to November 5 in green
and the following direct motion in red.
Charts generated with the assistance of GUIDE 8.0 produced by Project Pluto.
Uranus ...
The spacecraft encountered the lunar surface in direct motion along a hyperbolic trajectory, with an incoming asymptotic direction at an angle of -5.57 degrees from the lunar equator. The orbit plane was inclined 26.84 degrees to the lunar equator.
It will also come very close to being at the point of the 1846 discovery in late October through early-mid November 2010, when Neptune will switch from retrograde to direct motion on the exact degree of Neptune's discovery and will then be ...
If the galaxy is tilted at a random angle relative to our view, we have to take that into account when figuring out the velocity and therefore the mass of the galaxy, so it is always better to have direct motion toward or away from us.
The apparent retrograde and direct motion of the planets arises not from their motion but from the earth's. The motion of the earth alone, therefore, suffices to explain so many apparent inequalities in the heavens.
 See also: Apparent, Earth, Planet, Sun, Distance
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