July 27, 2012
Credits: NASA/JPL/Voyager 2 Mission - Credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/IPF
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Proteus was discovered from the images taken by the NASA - Voyager 2 Space Probe, just 2 (two) months before its short space encounter (a Fly-By) with Neptune, which occurred in the month of August of the AD 1989. This newly discovered Celestial Body received the temporary designation of S/1989 N1. The Astronomers Stephen P. Synnott and Bradford A. Smith (of the Voyager Science Team) announced its discovery on July 7, 1989, speaking only of “...an object seen in 17 frames taken over 21 days...”, which gives us a Discovery Date that could reasonably be located sometime before June 16, 1989. On the date of September, 16, 1991, S/1989 N1 was officially named Proteus, after the Greek Mythological "shape-changing" Marine Deity. Proteus orbits Neptune at a distance which is approximately equal to 4,75 Equatorial Radii of the Gas-Giant Planet (such as approx. 118.000 Km), calculated from Neptune's Cloud Tops. Its orbit has a small Eccentricity and is inclined by about 0,5° as to Neptune's Equator. Proteus is the largest of the so-called Regular Prograde Satellites of Neptune, and it rotates Synchronously with its Orbital Motion (which means that, just like our Moon - as well as almost all the known Natural Satellites of the Planets forming of our Solar System - it always points the same "Face" to its Parent Planet). Despite being more than 400 Km in diameter, Proteus has an obvious irregular shape, with several slightly Concave Facets and Surface Reliefs as high as 20 Km. Its Surface, as far as we know, is dark, likely neutral in color (but we, as IPF, speculate that it may be reddish) and heavily cratered. The largest known Impact Crater is more than 200 Km wide, but there are also a number of Scarps, Grooves and Valleys related to other large Impact Craters. Proteus is, most likely, not an Original Body of the Neptunian System (meaning a Rocky Celestial Body that formed at the same time of the entire Neptunian System itself), but rather a Celestial Body that accreted quite some time later. As a matter of fact, some Scientists speculate that Proteus formed from a Cloud of Debris that was created when the largest Neptunian Natural Satellite Triton was "Gravitationally Captured" by its Parent Planet; this means, in other words, that the orbit of Triton, upon its Gravitational Capture by Neptune, could have well been highly eccentric, and this fact caused Chaotic Gravitational -Tidal - Perturbations in the orbits of all the other Original Inner Neptunian Natural Satellites, causing them to repeatedly collide against one another, until they were reduced to a Disc of Rubble. Only after Triton's orbit stabilized, and such a "Planetary Chaos" ended, some part of the aforementioned Rubble Disc re-accreted into one or more of the present-day Natural Satellites of Neptune, including Proteus. Another possibility, instead, is that Proteus itself could be the result of a "Gravitational Capture": maybe, in this second scenario (which we, as IPF, believe that it is a little more Scientifically plausible than the first one), Proteus could have been a Kuiper's Belt Object - or "KBO" - that, for unknown reasons (but likely an impact), was pushed away from its original position and orbit, and then started moving towards the Inner Regions of the Solar System, until it arrived within the Gravitational Attracting Capacity (or "Gravitational Reach") of Neptune, that made it one of its many moons. This frame has been colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Voyager 2 Space Probe and then looked outside, towards the Neptunian moon Proteus), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. |
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