by iamlucky13 » Tue Mar 27, 2007 9:54 pm
It couldn't genuinely skip off Saturn's atmosphere and break orbit, but the upward force of half the planet skimming through progressively denser layers could cause it to skip outward. Since it would've lost some additional orbital velocity due to drag, it would then fall closer in, repeating this process (zero to who knows how many times) until it finally plunged in. On the other hand, an Apollo capsule, for example had enough velocity that it could've skipped off and enter orbit around the sun.
However, given Enceladus' orbital radius (a little smaller than our own moon), it would take a very, very long time for it's orbit to decay that far. As an example, Mars' moons Phobos orbits low enough to have a slight interaction with the martian atmosphere (I think this moons is believed to be a relatively recent capture, BTW), and also experiences tidal drag, but Phobos isn't expected to hit Mars for at least 50 million years.
As it's orbit fell, there is a chance tidal forces could tear it apart, forming a new ring.
If it did hit...dang.
The black spots from
Shoemaker-Levy 9 would pale in comparison, but give us some idea of what would happen as a whole. Basically all of its remaining kinetic energy would be converted into heat via drag. If the stress was great enough to fragment the moon, this could happen very quickly (in minutes). The heat would cause the gas giant's atmosphere to expand violently around the plummeting moon and a complex shock wave would probably circle the planet. Heavier, different-colored gas from deep within Saturn's atmosphere would be churned upward forming a distinctive mark, and the bands of clouds would probably be disrupted for years. Fragments of the destroyed moon and pockets of gas from Saturn could be blown out into other regions of the solar system, forming a cloud of debris visible for days or months, and causing Saturn to appear out-of-round shortly after the collision.
Doing some quick and very dirty math with BMAONE23's numbers, the moon currently has a kinetic energy of 1.6 E18 Joules. If that remained within a factor of 10 when it entered, the effect would be equivalent to a quintillion of the largest nuclear bombs ever made going off.
If any large pieces, or even the whole core of Enceladus survived the initial entry, I believe they would gradually collapse under their own weight to smaller sizes as they sank towards the center of Saturn. Depending on their density and the interior composition of Saturn, they could remain floating at various levels in Saturn's interior.
Actually, as I think about it more, Enceladus may actually gain orbital velocity from Saturn due to tidal forces, thus it would never fall inward. That would be a question best left to someone more initimately familiar with the Saturn system.
It couldn't genuinely skip off Saturn's atmosphere and break orbit, but the upward force of half the planet skimming through progressively denser layers could cause it to skip outward. Since it would've lost some additional orbital velocity due to drag, it would then fall closer in, repeating this process (zero to who knows how many times) until it finally plunged in. On the other hand, an Apollo capsule, for example had enough velocity that it could've skipped off and enter orbit around the sun.
However, given Enceladus' orbital radius (a little smaller than our own moon), it would take a very, very long time for it's orbit to decay that far. As an example, Mars' moons Phobos orbits low enough to have a slight interaction with the martian atmosphere (I think this moons is believed to be a relatively recent capture, BTW), and also experiences tidal drag, but Phobos isn't expected to hit Mars for at least 50 million years.
As it's orbit fell, there is a chance tidal forces could tear it apart, forming a new ring.
If it did hit...dang.
The black spots from [url=http://en.wikipedia.org/wiki/Shoemaker-Levy_9#Impacts]Shoemaker-Levy 9[/url] would pale in comparison, but give us some idea of what would happen as a whole. Basically all of its remaining kinetic energy would be converted into heat via drag. If the stress was great enough to fragment the moon, this could happen very quickly (in minutes). The heat would cause the gas giant's atmosphere to expand violently around the plummeting moon and a complex shock wave would probably circle the planet. Heavier, different-colored gas from deep within Saturn's atmosphere would be churned upward forming a distinctive mark, and the bands of clouds would probably be disrupted for years. Fragments of the destroyed moon and pockets of gas from Saturn could be blown out into other regions of the solar system, forming a cloud of debris visible for days or months, and causing Saturn to appear out-of-round shortly after the collision.
Doing some quick and very dirty math with BMAONE23's numbers, the moon currently has a kinetic energy of 1.6 E18 Joules. If that remained within a factor of 10 when it entered, the effect would be equivalent to a quintillion of the largest nuclear bombs ever made going off. :shock:
If any large pieces, or even the whole core of Enceladus survived the initial entry, I believe they would gradually collapse under their own weight to smaller sizes as they sank towards the center of Saturn. Depending on their density and the interior composition of Saturn, they could remain floating at various levels in Saturn's interior.
Actually, as I think about it more, Enceladus may actually gain orbital velocity from Saturn due to tidal forces, thus it would never fall inward. That would be a question best left to someone more initimately familiar with the Saturn system.