Search results
Results from the WOW.Com Content Network
The evolution of the apparent diameter and phases of Venus. A planetary phase is a certain portion of a planet's area that reflects sunlight as viewed from a given vantage point, as well as the period of time during which it occurs. The phase is determined by the phase angle, which is the angle between the planet, the Sun and the Earth.
Diagram showing the eastern and western quadratures of a superior planet like Mars. In spherical astronomy, quadrature is the configuration of a celestial object in which its elongation is a right angle (90 degrees), i.e., the direction of the object as viewed from Earth is perpendicular to the position of the Sun relative to Earth.
"Inferior planet" refers to Mercury and Venus, which are closer to the Sun than Earth is. "Superior planet" refers to Mars, Jupiter, Saturn, Uranus, and Neptune (the latter two added later), which are further from the Sun than Earth is. The terms are sometimes used more generally; for example, Earth is an inferior planet relative to Mars.
For some objects, such as the Moon (see lunar phases), Venus and Mercury the phase angle (as seen from the Earth) covers the full 0–180° range. The superior planets cover shorter ranges. For example, for Mars the maximum phase angle is about 45°. For Jupiter, the maximum is 11.1° and for Saturn 6°. [1]
At phase angles exceeding 90° (crescent phase) the brightness falls off especially sharply. The shape of the phase curve indicates a mean slope on the surface of Mercury of about 16°, [1] which is slightly smoother than that of the Moon. Approaching phase angle 0° (fully illuminated phase) the curve rises to a sharp peak.
Main page; Contents; Current events; Random article; About Wikipedia; Contact us
This template is part of a group of templates that are used to display information about the orbital characteristics of an extrasolar planetary system. The list should always have {{OrbitboxPlanet begin}} as the first in the list, while the list should have {{Orbitbox end}} as the last in the list. This particular template can be used as follows:
No description. Template parameters [Edit template data] Parameter Description Type Status Title title no description Unknown optional Image image no description Unknown optional Image scale image_scale no description Unknown optional Alt text for image image_alt no description Unknown optional Image caption caption no description Unknown optional Background color background color bgcolour no ...