December 2022 Newsletter

April 2023 Newsletter

The closest approach distance is not the only important parameter for assessing the asteroid hazard. The velocity plays a crucial role in shaping the outcome of a close encounter as well as in evaluating the consequences of an impact. The speed at which an asteroid flies by the Earth results from geometrical and dynamical considerations characterizing its pre-encounter orbit.

Ten years ago, on 6 October 2008,Richard Kowalski, an observer of the Catalina Sky Survey, spotted the first-ever asteroid found on an imminent collision course with the Earth. Over the following hours, hundreds of astrometric observations, plus light curves and spectroscopic data, were collected by observers all over the world.

The asteroid ground track is provided below starting one day before the closest approach and extending for 1.5 days. The curve represents the movement of the sub-asteroid point over the Earth along the mentioned time interval. The track starts in the Pacific ocean at magnitude 16 and progresses westwards.

February 2021 Newsletter