DART: Planetary Defense in the Introductory Physics Curriculum

• Joseph C. Amato ^[1]
  1. [1] Colgate University

     Colgate University

     Town of Hamilton, Estados Unidos

     
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 60, Nº. 6, 2022, págs. 406-409
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The Double Asteroid Redirection Test (DART) is a National Aeronautics and Space Administration–European Space Agency collaborative mission to test the feasibility of defending Earth from a catastrophic asteroid impact by using a spacecraft to deflect the asteroid away from the planet. Launched on Nov. 23, 2021, the DART spacecraft will intercept the binary asteroid 65803 Didymos in late September or early October 2022, colliding (nearly) head-on to modify its motion measurably.1 The DART mission would be an ideal supplement to the standard textbook treatment of a one-dimensional inelastic collision involving blocks sliding over a frictionless surface. It is certain to fascinate students and—in contrast to colliding blocks—vividly illustrate the contemporary, real-world importance of momentum conservation.

    But the physics of the DART mission is even richer, addressing Kepler’s laws, energy conservation, and orbital dynamics as well as momentum conservation, topics that are all included in a first-year mechanics course. DART could be an ideal end-of-semester review topic or the focus of a final examination question. In the following, we will describe the physics of DART in simplified form, as appropriate for either of these purposes. We first review the orbital motions of the spacecraft and the two bodies comprising the asteroid, and then calculate the change in the latter due to the collision. Finally, we expand the discussion beyond simple one-dimensional inelastic collisions to include those that are not head-on, or where a significant mass of matter is blasted off the asteroid surface after impact—as expected for DART.