Discovered in 1851 by William Lassell, Ariel is the brightest satellite of Uranus. Ariel is 191,240 kilometers from Uranus and has an equatorial radius of 578.9 kilometers. The surface bears many heavy impact craters from millions of years of meteorite impact.
In addition, there are long, deep rift valleys that extend across the surface, much like that on Mars. The bases of the valleys have been smoothed by a fluid (not water), possibly ammonia, methane or carbon monoxide.
|PHYSICAL DATA FOR ARIEL|
|Mass (kg)||1.27e + 21|
|Mass (Earth = 1)||2.1252e - 04|
|Radius (Earth = 1)||9.0765e - 02|
|Mean Density (g/cm3)||1.56|
|Mean Distance from Uranus (km)||191,240|
|ORBITAL DATA FOR ARIEL|
|Rotational period (days)||2.520379|
|Orbital period (days)||2.520379|
|Mean orbital velocity (km/s)||5.52|
|Orbital inclination (degrees)||0.31|