Dear Small Bodies Colleagues,

SBAG is convening a Specific Action Team (SAT) to study the scientific opportunities surrounding Asteroid (99942) Apophis’s Earth close approach on April 13, 2029. We are seeking subject matter experts in small-body science, especially (but not necessarily limited to) geophysics, dynamics, mechanical/material properties, astronomical observations, and flight instrumentation.

The SBAG Steering Committee intends to have a list of SAT members selected for concurrence by NASA’s Planetary Science Division by November 1, 2021. The SAT should deliver the report from its study to the NASA Planetary Science Division Director by August 2022.

The draft Statement of Task directs the Specific Action Team (SAT) to conduct a study to:

  1.  Identify and quantify the detectable effects on Apophis expected to result from the Earth encounter, and identify the measurements and instrumental sensitivities needed to detect them and determine their magnitudes;

  2.  Assess and prioritize the importance to planetary science and planetary defense of detecting and measuring each of these effects, as well as the value of non-detections (upper limits);

  3.  Categorize these effects according to (a) detectable using Earth-based assets, (b) detectable using a spacecraft arriving only after Earth close approach, (c) detectable using a spacecraft arriving before Earth close approach; and

  4.  Quantitatively assess the possibility that spacecraft sent to Apophis could increase the risk of a future Earth impact.

But the study should not:

  1.  Assess, prioritize, or recommend specific instruments, facilities, flight hardware, mission profiles or concepts; or

  2.  Consider observations or measurements that are not specific to the physical effects of the Earth encounter, unless communication advantages afforded by the close proximity to Earth would enable unique measurements that would otherwise be impossible.

Members of the SBAG community can self-nominate or nominate others for membership on the SAT by sending a short statement (no more than 200 words) describing their experience relevant to the draft Statement of Task above to the SBAG Chair ([email protected]) by October 5, 2021. We are especially encouraging early-career people with relevant experience to apply.

Bonnie J. Buratti, PhD

JPL Research Fellow, Senior Research Scientist, and Principal Manager Planetary Sciences Section Chair, Small Bodies Assessment Group (SBAG) NASA Jet Propulsion Laboratory, California Institute of Technology Pasadena, CA 91109