Spacecraft That Went to Mars



However, Dr. Thomas explained to the press in May 2013 that the ring arcs are much more tenuous than the fully formed rings of Saturn. As a matter of fact, the ring arcs are so delicate and thin that it would take about ten billion years for just 1 meter of blowing icy snow to collect within the craters of Methone. Organic dust forms when organic molecules, resulting from the interaction of sunlight with methane, grow large enough to tumble down to the surface of Titan. Dr. Roderiguez continued to explain that, even though this is the first-ever observation of a dust storm on Titan, the discovery is not especially surprising. There are over 100 moons dancing around the eight major planets of our Sun's family. Most of them are small, frozen, icy objects, harboring only a relatively scanty amount of rocky material, that circle around the quartet of giant gaseous planets that dwell in the outer, frigid realm of our Solar System--far from the comforting warmth and brilliance of our Star. The quartet of majestic, giant denizens of our outer Solar System--Jupiter, Saturn, Uranus, and Neptune--are enveloped with gaseous atmospheres, and orbited by a multitude of dancing, sparkling moons and moonlets. In marked contrast, the inner region of our Solar System--where our Earth dwells--is almost bereft of moons. Of the quartet of relatively petite, rocky "terrestrial" planets--Mercury, Venus, Earth, and Mars--only Earth is circled by a large Moon. Mercury and Venus are moonless, and Mars is orbited by a duo of tiny, lumpy, potato-shaped moons, Phobos and Deimos. Phobos and Deimos are probably escaped asteroids, born in the Main Asteroid Belt between Mars and Jupiter, that were captured by the gravitational embrace of the Red Planet long ago.