Timeline for How did astronomers determine the path of 'Oumuamua so quickly?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
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| Aug 16, 2018 at 21:56 | comment | added | James K | When you determine an orbit there might be more than one orbital solution. (It does involve solving a degree 8 polynomial) We can try to constrain the possible solutions by assuming the object is not an earth satellite, and not interstellar. Finding the orbit for 'Oumuamua was a problem because it the software for finding orbits makes this assumption. But you can still find an orbit that is interstellar, you just need to change your assumptions. | |
| Aug 16, 2018 at 21:34 | comment | added | jkade | I'm a little confused. Gronchi et al.'s very helpful paper on classical and modern orbit determination, in its section on modern solutions for problematic orbits where Gauss's hypotheses don't apply, specifically excludes interstellar objects: copernico.dm.unipi.it/~gronchi/PDF/gronchi_discuss.pdf Was 'Oumuamua different because it passed close enough to the sun that it was similar enough to a solar system object? | |
| Jun 7, 2018 at 1:21 | comment | added | Florin Andrei | James is right. The three-point method (augmented with extra points when possible) is canonical, and can be done using traditional instruments. Even amateurs can use it. It's sometimes called Gauss' method, and was used for the first time to determine the orbit of Ceres. | |
| Jun 6, 2018 at 5:47 | comment | added | James K | If we can observe it, we can fit an orbit to the observations. No upper or lower limits. There might be exceptional situations in which more than one sensible orbit can fit a small number of observations. Everything gets perturbed, but most orbits are very close to ellipses, or hyperbolae | |
| Jun 5, 2018 at 23:57 | comment | added | jkade | Is there any path that an interstellar asteroid could take through the easily observable solar system that we couldn't extrapolate? Is there a lower limit on the orbital eccentricity we could use to determine an object's trajectory? I take it that an object would have to be significantly more massive than the sun to pass through the solar system without its course being perturbed? | |
| Jun 5, 2018 at 22:27 | vote | accept | jkade | ||
| Jun 5, 2018 at 19:54 | comment | added | James K | You need radar to do that. | |
| Jun 5, 2018 at 17:27 | comment | added | user21 | In theory, you can determine orbital elements from one observation of position and velocity (arguably, measuring velocity would itself require two observations): naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/oscltx_c.html -- however, as the linked page itself warns, the results can be far from accurate, and, obviously, averaging out multiple observations is always a good idea. | |
| Jun 4, 2018 at 18:21 | history | answered | James K | CC BY-SA 4.0 |