Yesterday, the media reported widely on the upcoming launch of OSIRIS-REx. While many of these reports were accurate and informative, a few of the headlines were a little misleading. For example:
NASA Spacecraft Set to Explore Giant Asteroid That Could Destroy Earth
Fortunately, as the news cycle progressed, these inaccuracies were corrected:
No, Asteroid Bennu Won’t Destroy Earth
I thought it would be useful to summarize the effects of a Bennu impact. The Minor Planet Center classifies Bennu as a Potentially Hazardous Asteroid because it has a diameter larger than 150 m and a minimum orbit intersection distance (MOID) of < 0.05 Astronomical Units (abbreviated AU and equal to the average distance between the Earth and Sun) with the Earth. Bennu has a mean diameter of 492 meters and its MOID is 0.003 AU. The MOID will steadily decrease resulting in a potential Earth impact during the later decades of the 22nd century. The tabulation of potential Earth impacts results in a cumulative impact probability of approximately 1 in 2700 sometime in the 2175– 2196 time frame.
I used the Impact Earth! calculator provided by Purdue University and Imperial College London to assess the results of a Bennu impact. For ...