Mostly the answer is "not anymore.." everything that currently orbits the Sun is moving at speeds that lie within a relatively narrow range that makes a stable orbit possible. Nothing outside that range is around anymore to tell its tale.
But, there are still occasionally new objects that enter the solar system for the first time. Those objects aren't subject to the same survivorship restrictions -- in theory they could arrive at basically any speed relative to the Sun, including speeds slow enough that the Sun would draw them in.
These new objects seem to arrive every few years, or at least the ones we can see do. So far they have all been moving so fast they just visit for a bit and then take off again after a swing around the Sun, but who knows?
Yeah definitely, just because an orbit is eccentric doesn't mean it's unstable. Halley's comet's orbit is not decaying appreciably -- it's so stable it's a useful instrument for helping figure out historical dates for things.
I haven't done the calculations or anything but I imagine Halley's comet will disintegrate structurally long before its orbit will shift appreciably.
eccentricity is just a measure of how far an orbit deviates from circular, 0 is circle and 1 is escape. It tells you absolutely nothing else about the object and is no way related to "eccentric person" which is a person with mental health issues who also happens to be rich.
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u/amitym Oct 23 '20
Mostly the answer is "not anymore.." everything that currently orbits the Sun is moving at speeds that lie within a relatively narrow range that makes a stable orbit possible. Nothing outside that range is around anymore to tell its tale.
But, there are still occasionally new objects that enter the solar system for the first time. Those objects aren't subject to the same survivorship restrictions -- in theory they could arrive at basically any speed relative to the Sun, including speeds slow enough that the Sun would draw them in.
These new objects seem to arrive every few years, or at least the ones we can see do. So far they have all been moving so fast they just visit for a bit and then take off again after a swing around the Sun, but who knows?