Timeline for How close to escape velocity are most Oort-cloud comets?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 24, 2021 at 23:32 | vote | accept | WarpPrime | ||
| Dec 17, 2021 at 22:14 | history | edited | notovny | CC BY-SA 4.0 |
Completed truncated first sentence.
|
| Dec 17, 2021 at 21:15 | comment | added | notovny | @AtmosphericPrisonEscape If an object at perihelion $r_p$ is moving at $v_p=\sqrt{\frac{\mu}{r_p}}$, then that orbit must be circular. For an elliptical orbit, it will always be moving faster than that speed at perihelion, which invalidates your $1/\sqrt{2}$ ratio claim. Under the Keplerian-Newtonian two-body simplifications, any velocity of magnitude less than the local escape velocity, in any direction results, in an elliptical orbit. | |
| Dec 17, 2021 at 20:52 | comment | added | AtmosphericPrisonEscape | Just that velocity at perihelion is not a radial one, but a tangential one, as the object has to orbit. Furthermore, the approximation for large a is only valid in the approximation of infinite eccentricity, which is not given for all small solar system bodies. | |
| Dec 17, 2021 at 19:55 | comment | added | notovny | @AtmosphericPrisonEscape Both of your statements are incorrect. The Vis-viva equation works for all Keplerian orbits and trajectories, as along as you're using negative semi-major axis for hyperbolic trajectories. Escape velocity /$\sqrt{2}$ = the circular orbit velocity for the chosen distance, only. | |
| Dec 17, 2021 at 19:46 | comment | added | AtmosphericPrisonEscape | Any object obeying the vis-viva equation is bound to the star, anything bound has a factor of $1/\sqrt(2)$ between its perihelion velocity and the escape velocity at perihelion... | |
| Dec 17, 2021 at 18:58 | comment | added | planetmaker | Very nice explanation. In essence: it's just jumping a frog off the comet to trigger it :) | |
| Dec 17, 2021 at 17:54 | history | edited | notovny | CC BY-SA 4.0 |
added 804 characters in body
|
| Dec 17, 2021 at 17:11 | history | answered | notovny | CC BY-SA 4.0 |