Systematic ranging and late warning asteroid impacts

Abstract

We describe systematic ranging, an orbit determination technique especially suitable to assess the near-term Earth impact hazard posed by newly discovered asteroids. For these late warning cases, the time interval covered by the observations is generally short, perhaps a few hours or even less, which leads to severe degeneracies in the orbit estimation process. The systematic ranging approach gets around these degeneracies by performing a raster scan in the poorly-constrained space of topocentric range and range rate, while the plane of sky position and motion are directly tied to the recorded observations. This scan allows us to identify regions corresponding to collision solutions, as well as potential impact times and locations. From the probability distribution of the observation errors, we obtain a probability distribution in the orbital space and then estimate the probability of an Earth impact. We show how this technique is effective for a number of examples, including 2008 TC3 and 2014 AA, the only two asteroids to date discovered prior to impact.

References in corpus (1)

• Efficient intra- and inter-night linking of asteroid detections using kd-trees

Cited by in corpus (6)

• Near-Earth Object Orbit Linking with the Large Synoptic Survey Telescope
• The digest2 NEO Classification Code
• Ground-based astrometry calibrated by Gaia DR1: new perspectives in asteroid orbit determination
• Homing in for New Year: impact parameters and pre-impact orbital evolution of meteoroid 2014 AA
• The observing campaign on the deep-space debris WT1190F as a test case for short-warning NEO impacts
• A systematic ranging technique for follow-ups of NEOs detected with the Flyeye telescope