You’ve probably read about this unprecedented visitor from inter-stellar space. I thought you’d like to see its trajectory through our solar system.
(Enlarge as much as you can.)
My diagram shows the paths of the four inner planets in October, November, and December of 2017. The path of Oumuamua is shown from August onward, in magenta before its 2017 Oct. 19 discovery, and then in yellow. Stalks connect it to the ecliptic plane at the beginning of each month.
It arrived from the north, at an angle of about 33° (its “inclination” of 123°, or 90°+33°, means that the direction is retrograde – opposite to the general motion of the planets). As with all travelers on huge orbits, like long-period comets, only the innermost, shortest, speediest part of the orbit is on the other side of the plane.
It descended through the plane on Aug. 24, inside the orbit of Mercury; was at perihelion (closest point to the Sun) on Aug. 30. If you look closely you can see a sunward tick at that point. It ascended back through the plane on Oct. 13, well outside Earth’s orbit.
It was nearest to Earth (0.276 a.u.) on Oct. 8. A green line connects it to Earth at the nearest moment, which was some days before the discovery.
The view is from 15° north of the ecliptic plane, from a longitude of 350°, and from a distance of 6 astronomical units (Sun-Earth distances). The planets are exaggerated 500 times in size, the Sun 5 times. The dashed line shows the vernal equinox direction (the zero point for sky mapping).
That’s enough for now. It was easier than I expected to find orbital elements and make them work, but I’ve had to spend more than half the day (the day before Christmas). There is of course more to be said about this 250-yard-long hurtling red rock that has been given the Hawai’ian name ‘Oumuamua, and I expect I” say may some of it tomorrow or the day after.