A roughly circular albedo spot on icy satellites that is presumed to mark the site of a crater and its rim deposit. Little, if any, of the topographic structure exists, but visual distinction from adjacent crust remains.
Literally "swamp"; really a small plain.
= 206265 AU = 3.26 light year
A shallow crater; scalloped, complex edge.
Literally, "dim light"; the outer filamentary region of a sunspot.
The orbital point of closest approach to the Sun.
To cause a planet or satellite to deviate from a theoretically regular orbital motion.
The accurate quantitative measurement of the amount of light received from an object or area.
The visible surface of the Sun; sunspots and faculae are observed in the photosphere.
Contraction of "picture element"; the area on the ground represented by each digital number in a digitized image; an individual element in a detector.
A spherical ball of rock and/or gas that orbits a star. The Earth is a planet. Our solar system has nine planets. These planets are, in order of increasing average distance from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto.
Primordial bodies of intermediate size that accreted into planets or asteroids.
A low plain.
A plateau or high plain.
A geological model in which the Earth's lithosphere (crust and uppermost mantle) is divided into a number of more-or-less rigid segments which move in relation to one another.
The measurement and study of the polarization of light reflected off of a surface.
A measure of the amount of work done per second, expressed in Watts.
A strand of relatively cool gas in the solar corona which appears bright when seen at the edge of the Sun against the blackness of space.
A cape or headland.