The views expressed in this report are those of the authors. Their statements are not necessarily endorsed by the affiliated organisations or the Global Challenges Foundation.

There is currently a worldwide effort underway to search the sky for Near-Earth Objects (NEOs). While the bulk of discoveries are made by ground-based telescopes funded by the US National Aeronautics and Space Administration (NASA) and operated in the United States, other recent discovery sites include Morocco, Brazil, China and Japan. After an object is discovered, follow up observations undertaken by dozens of observatories around the world are collected to perform precise orbital calculations, which in turn allows analysis to quantify the risk. Should an impact be predicted with sufficient warning time, several techniques are being studied (both by the NASA Planetary Defense Coordination Office and the European Union’s NEOShield-2 project) that may allow successful deflection of an object away from an impacting trajectory. Even if an impact is imminent, evacuation of the impact zone would allow people to escape harm if they are able to move a sufficient distance, and if the size of the object is such that only local damage is expected.

NASA is a signatory to the International Asteroid Warning Network (or IAWN), and as such part of a United Nations-endorsed effort established through the work of the Committee on the Peaceful Uses of Outer Space (COPUOS) that currently includes at least 10 different efforts around the world focusing on asteroid defense, communication, and education. Membership in the IAWN is non-binding and voluntary but it enables data to be collected worldwide, consolidated and analyzed, and the resulting information is released to all UN COPUOS member states.  

Should an impact be predicted with sufficient warning time, several techniques are being studied that may allow successful deflection.

The United States Congress has directed NASA to find at least 90% of all asteroids larger than 140 meters whose orbits could lead to an impact with Earth. NASA funds several survey teams in the United States specifically to search for asteroids. NASA also funds the Minor Planet Center, which serves as an international clearing house for asteroid-related data, as well as the JPL Center for NEO Studies, which computes high-precision orbits and evaluates the impact hazard from each object. NASA requires, as a condition for continued funding, that all data and data products from asteroid surveys and orbit computations be made available in the public domain. 

In other countries, surveys often operate on a voluntary basis, with no binding mechanism to force data submission to the MPC. However, as the MPC is currently recognized as the worldwide clearing house for asteroid data, and on the basis of the International Astronomical Union’s rules for asteroid naming rights, the desire of all individuals involved in contributing to the inventory of NEOs tends to drive them to submit data for publication.

In the field of NEO discovery and tracking, there are few if any non-formal mechanisms in place. A few mailing lists support discussion of the subject, as well as occasional meetings bringing together members of the professional community with enthusiast astronomers. The latter, often unpaid amateurs, through the supply of observations, support the research conducted mainly by professional astronomers in the United States and, to a somewhat lesser extent, in Europe.

Tim Spahr

CEO of NEO Sciences, LLC, former Director of the Minor Planetary Center, Harvard-Smithsonian Center for Astrophysics