Roberto Gorelli points our attention at a recently published meteor related paper.
Discovery of a Meteor of Interstellar Origin
This paper has been submitted for publication by Amir Siraj and Abraham Loeb.
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 ∼ 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 ∼ 0.45m meteor detected at 2014-01-08 17:05:34 UTC as originating from an unbound hyperbolic orbit with 99.999% confidence. We infer that the meteor had an asymptotic speed of v∞ ∼ 42.1±5.5 km s^−1 outside of the solar system. Its origin is approximately towards R.A. 49.4±4.1° and declination 11.2 ± 1.8°, implying that its initial velocity vector was 58 ± 6 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 AU^-3 or 9 × 10^21 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.
You can download this paper for free: https://arxiv.org/pdf/1904.07224.pdf (5 pages).