{
  "id": "1904.07224",
  "version": "v1",
  "published": "2019-04-15T17:59:59.000Z",
  "updated": "2019-04-15T17:59:59.000Z",
  "title": "Discovery of a Meteor of Interstellar Origin",
  "authors": [
    "Amir Siraj",
    "Abraham Loeb"
  ],
  "comment": "4 pages, 2 figures; submitted to ApJ",
  "categories": [
    "astro-ph.EP"
  ],
  "abstract": "The first interstellar object, `Oumuamua, was discovered in the Solar System by Pan-STARRS in 2017, allowing for a calibration of the abundance of interstellar objects of its size $\\sim 100\\;$ m. One would expect a much higher abundance of smaller interstellar objects, with some of them colliding with Earth frequently enough to be noticeable. Based on the CNEOS catalog of bolide events, we identify the $\\sim 0.45$m meteor detected at 2014-01-08 17:05:34 UTC as originating from an unbound hyperbolic orbit with an asymptotic speed of $v_{\\infty} \\sim 43.8\\; \\mathrm{km \\; s^{-1}}$ outside of the solar system. Its origin is approximately towards R.A. 3h24m and declination $+10.4^{\\circ}$, implying that its initial velocity vector was $\\sim 60\\; \\mathrm{km\\;s^{-1}}$ away from the velocity of the Local Standard of Rest (LSR). Its high LSR speed implies a possible origin from the deep interior of a planetary system or a star in the thick disk of the Milky Way galaxy. The local number density of its population is $10^{6{^{+0.75}_{-1.5}}} \\; \\mathrm{AU^{-3}}$ or $9 \\times 10^{21{^{+0.75}_{-1.5}}} \\; \\mathrm{pc^{-3}}$ (necessitating 0.2 - 20 Earth masses of material to be ejected per local star). This discovery enables a new method for studying the composition of interstellar objects, based on spectroscopy of their gaseous debris as they burn up in the Earth's atmosphere.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-04-15T17:59:59.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "interstellar origin",
      "solar system",
      "smaller interstellar objects",
      "first interstellar object",
      "unbound hyperbolic orbit"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 4,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}