The Outer Solar System Origins Survey (OSSOS), a wide-field imaging program in 2013-2017 with the CanadaFrance-Hawaii Telescope, surveyed 155 deg 2 of sky to depths of m r = 24.1-25.2. We present 838 outer solar system discoveries that are entirely free of ephemeris bias. This increases the inventory of trans-Neptunian objects (TNOs) with accurately known orbits by nearly 50%. Each minor planet has 20-60 Gaia/Pan-STARRS-calibrated astrometric measurements made over 2-5 oppositions, which allows accurate classification of their orbits within the trans-Neptunian dynamical populations. The populations orbiting in mean-motion resonance with Neptune are key to understanding Neptune's early migration. Our 313 resonant TNOs, including 132 plutinos, triple the available characterized sample and include new occupancy of distant resonances out to semimajor axis a ∼ 130 au. OSSOS doubles the known population of the nonresonant Kuiper Belt, providing 436 TNOs in this region, all with exceptionally high-quality orbits of a uncertainty σ a 0.1%; they show that the belt exists from a  37 au, with a lower perihelion bound of 35au. We confirm the presence of a concentrated low-inclination a ; 44 au "kernel" population and a dynamically cold population extending beyond the 2:1 resonance. We finely quantify the survey's observational biases. Our survey simulator provides a straightforward way to impose these biases on models of the trans-Neptunian orbit distributions, allowing statistical comparison to the discoveries. The OSSOS TNOs, unprecedented in their orbital precision for the size of the sample, are ideal for testing concepts of the history of giant planet migration in the solar system.

The scattering trans-Neptunian Objects (TNOs) can be measured to smaller sizes than any other distant small-body population. We use the largest sample yet obtained, 68 discoveries, primarily by the Outer Solar System Origins Survey (OSSOS), to constrain the slope of its luminosity distribution, with sensitivity to much fainter absolute H-magnitudes than previous work. Using the analysis technique in Shankman et al., we confirm that a single slope for the H-distribution is not an accurate representation of the scattering TNOs and Centaurs, and that a break in the distribution is required, in support of previous conclusions. A bright-end slope of α b =0.9 transitioning to a faintend slope α f of 0.4-0.5 with a differential number contrast c from 1 (a knee) to 10 (a divot) provides an acceptable match to our data. We find that break magnitudes H b of 7.7 and 8.3, values both previously suggested for dynamically hot Kuiper Belt populations, are equally non-rejectable for a range of α f and c in our statistical analysis. Our preferred divot H-distribution transitions to α f =0.5 with a divot of contrast c=3 at H b =8.3, while our preferred knee H-distribution transitions to α f =0.4 at H b =7.7. The intrinsic population of scattering TNOs required to match the OSSOS detections is 3×10 6 for H r <12, and 9×10 4 for H r <8.66 (D100 km), with Centaurs having an intrinsic population two orders of magnitude smaller.

During the formation and evolution of the Solar System, significant numbers of cometary and asteroidal bodies were ejected into interstellar space 1, 2 . It can be reasonably expected that the same happened for planetary systems other than our own. Detection of such Interstellar Objects (ISOs) would allow us to probe the planetesimal formation processes around other stars, possibly together with the effects of long-term exposure to the interstellar medium.